Exhibit No

EXHIBIT 4.18

MBIA INSURANCE CORPORATION

FINANCIAL GUARANTEE INSURANCE POLICY
May 16, 2003

Policy No. 41233

MBIA INSURANCE CORPORATION (“MBIA”), for consideration received, hereby unconditionally and irrevocably guarantees to the Beneficiary, subject only to the terms of this Financial Guarantee Insurance Policy (the “Policy”), payment of the Insured Obligation. MBIA agrees to pay to the Indenture Trustee, in respect of each Distribution Date, an amount equal to the amount by which (A) the sum of the following amounts, each as of or with respect to such Distribution Date, (i) the Servicing Fee, including any unpaid Servicing Fees, (ii) any accrued and unpaid fees of the Indenture Trustee, the Owner Trustee and the Trust Agent, in each case to the extent such fees have not been paid by the Servicer, (iii) the Note Interest Distributable Amount, and (iv) if such Distribution Date is a Final Scheduled Distribution Date with respect to any Class of Notes, the Note Principal Distributable Amount with respect to such Class of Notes exceeds (B) the sum of (i) the amount of Net Collections available to make such payments with respect to such Distribution Date, (ii) the amount on deposit in the Spread Account as of such Distribution Date (the “Deficiency Amount”) and (iii) amounts transferred from the Prefunding Account and the Capitalized Interest Account to the Payment Account with respect to such Distribution Date. MBIA also agrees to pay an amount equal to any Avoided Payment (as defined below). This Policy does not cover shortfalls, if any, attributable to the liability of the

Trust for withholding taxes, if any (including interest and penalties in respect of such liability). Payments hereunder shall be made only at the time set forth in this Policy. This Policy shall not guarantee payments of principal on the Notes other than the outstanding principal amount of each class of Notes on the Note Final Scheduled Distribution Date for such class of Notes, and will not guarantee payment of any Accelerated Principal Distributable Amount or amounts that become due on an accelerated basis as a result of (a) a default by the Trust, (b) the occurrence of an Indenture Event of Default under the Indenture, or (c) any other cause. MBIA may elect, in its sole discretion, to pay in whole or in part such principal due upon acceleration. MBIA may elect, in its sole discretion, to pay all or a portion of any shortfalls in the amount of Net Collections available to make distributions of principal on the Notes, other than distributions of principal with respect to a Class of Notes on the Final Scheduled Distribution Date therefor, which is guaranteed by MBIA as provided above.

     Capitalized terms used herein and not otherwise defined herein shall have the meanings assigned to them in the Sale and Servicing Agreement dated as of May 1, 2003 among Onyx Acceptance Financial Corporation, as seller (the “Seller”), Onyx Acceptance Corporation, as servicer (the “Servicer”) and custodian, Citibank, N.A., as Indenture Trustee and Trust Agent and the Trust (the “Sale and Servicing Agreement”).

     As used herein the term “Owner” means each Noteholder who on the applicable Distribution Date is entitled under the terms of the related Note to receive payments thereunder.

     Payment of amounts hereunder shall be made in immediately available funds on the later of (a) 12:00 noon, New York City time, on the related Distribution Date and (b) 12:00 noon, New York City time, on the second Business Day following presentation to State Street Bank and Trust Company, N.A., as Fiscal Agent for MBIA or any successor fiscal agent appointed by MBIA (the “Fiscal Agent”) (as hereinafter provided) and MBIA of a notice for payment in the form of Exhibit A hereto (“Notice for Payment”), appropriately completed and executed by the Indenture Trustee. A Notice for Payment under this Policy may be presented to the Fiscal Agent and MBIA on any Business Day following the Servicer Report Date in respect of which the Notice for Payment is being presented, by (a) delivery of the original Notice for Payment to the Fiscal Agent and MBIA at its respective address set forth below, or (b) facsimile transmission of the original Notice for Payment to the Fiscal Agent and MBIA at its respective facsimile number set forth below. If presentation is made by facsimile transmission, the Indenture Trustee shall (i) simultaneously confirm transmission by telephone to the Fiscal Agent and MBIA at its respective telephone number set forth below, and (ii) as soon as reasonably practicable, deliver the original Notice for Payment to the Fiscal Agent and MBIA at its respective address set forth below. Any Notice for Payment received by the Fiscal Agent or MBIA after 12:00 noon, New York City time, on a Business Day, or on any day that is not a Business Day, will be deemed to be received by the Fiscal Agent and MBIA on the next succeeding Business Day.

     Subject to the foregoing, if the payment of any amount previously distributed to an Owner in respect of the Notes that is recoverable and sought to be recovered as a voidable preference by a trustee in bankruptcy with respect to the Trust, the Seller or Onyx pursuant to the United States Bankruptcy Code (11 U.S.C.), as amended from time to time, in accordance with a nonappealable order of a court having competent jurisdiction is voided (“Avoided Payment”), MBIA will make such Avoided Payment on behalf of the Owner to the receiver, conservator,

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debtor-in-possession or trustee in bankruptcy named in the Final Order (as defined below) and not to any Owner directly, unless such Owner has previously paid such Avoided Payment to the receiver, conservator, debtor-in-possession or trustee in bankruptcy, in which case MBIA will make such Avoided Payment to such Owner upon receipt by the Fiscal Agent and MBIA from the Indenture Trustee on behalf of such Noteholder of (i) a certified copy of a final, nonappealable order of a court having competent jurisdiction to the effect that the Owner is required to return any such payment or portion thereof prior to the Termination Date of this Policy because such payment was voided under applicable law (the “Final Order”) together with an opinion of counsel satisfactory to MBIA that such Final Order is final and not subject to appeal, (ii) an assignment, substantially in the form attached hereto as Exhibit B, properly completed and executed by such Owner irrevocably assigning to MBIA all rights and claims of such Owner relating to or arising under such Avoided Payment, (iii) a Notice for Payment in the form of Exhibit A hereto appropriately completed and executed by the Indenture Trustee and (iv) appropriate instruments to effect the appointment of MBIA as agent for such Owner in any legal proceeding relating to such Avoided Payment.

     MBIA shall make payments due in respect of Avoided Payments no later than 12:00 noon, New York City time on the Business Day following the Fiscal Agent’s and MBIA’s receipt of the documents required under clauses (i) through (iv) of the preceding paragraph. Any such documents received by the Fiscal Agent or MBIA after 12:00 noon, New York City time, on any Business Day or on any day that is not a Business Day shall be deemed to have been received by the Fiscal Agent and MBIA prior to 12:00 noon on the next succeeding Business Day. All payments made by MBIA hereunder on account of any Avoided Payment shall be made to the receiver or the trustee in bankruptcy named in the Final Order on behalf of Owner and not to any owner directly unless such Owner has returned such Avoided Payment to such receiver or trustee in bankruptcy, in which case such payment will be disbursed to such Owner.

     If any Notice for Payment received by the Fiscal Agent and MBIA is not in proper form or is otherwise insufficient for the purpose of making a claim hereunder, it shall be deemed not to have been received by the Fiscal Agent and MBIA, and the Fiscal Agent or MBIA shall promptly so advise the Indenture Trustee, and the Indenture Trustee may submit an amended Notice for Payment.

     Payments due hereunder unless otherwise stated herein will be disbursed by the Fiscal Agent to the Indenture Trustee on behalf of the Owners by wire transfer of immediately available funds in the amount of such payment, less, in respect of Avoided Payments, any amounts held by the Indenture Trustee for the payment of such Avoided Payment and legally available therefor.

     The Fiscal Agent is the agent of MBIA only, and the Fiscal Agent shall in no event be liable to Owners for any acts of the Fiscal Agent or any failure of MBIA to deposit or cause to be deposited sufficient funds to make payments due under this Policy.

     MBIA shall be subrogated to the rights of each Owner to receive payments under the Notes to the extent of any payment by MBIA hereunder.

     MBIA hereby waives and agrees not to assert any and all rights to require the Indenture

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Trustee to make demand on or to proceed against any person, party or security prior to the Indenture Trustee demanding payment under this Policy.

     No defenses, set-offs and counterclaims of any kind available to MBIA so as to deny payment of any amount due in respect of this Policy will be valid and MBIA hereby waives and agrees not to assert any and all such defenses, set-offs and counterclaims, including, without limitation, any such rights acquired by subrogation, assignment or otherwise. Any rights of subrogation acquired by MBIA as a result of any payment made under this Policy shall, in all respects, be subordinate and junior in right of payment to the prior indefeasible payment in full of all amounts due the Indenture Trustee on account of payments due under the Notes.

     MBIA’s obligations under this Policy shall be discharged to the extent funds to pay the Insured Obligation are deposited by the Servicer into the Collection Account in accordance with the Sale and Servicing Agreement or disbursed by MBIA as provided in this Policy, whether or not such funds are properly applied by the Indenture Trustee.

     This Policy is neither transferable nor assignable, in whole or in part, except to a successor to the Indenture Trustee pursuant to the Indenture. All notices, presentations, transmissions, deliveries and communications made by the Indenture Trustee to MBIA with respect to this Policy shall specifically refer to the number of this Policy and shall be made to MBIA at:

or such other address, telephone number or facsimile number as MBIA may designate to the Indenture Trustee in writing from time to time. Each such notice, presentation, transmission, delivery and communication shall be effective only upon actual receipt by MBIA.

     All notices, presentations, transmissions, deliveries and communications made by the Indenture Trustee to the Fiscal Agent of MBIA shall specifically refer to the number of this Policy and shall be made at the address listed below for the Fiscal Agent of MBIA or such other address, telephone number or facsimile number as MBIA or the Fiscal Agent shall specify in writing to the Indenture Trustee.

     The notice address of the Fiscal Agent is 61 Broadway, 15th Floor, New York, New York 10006 Attention: Municipal Registrar and Paying Agency, Telephone: 212 ###-###-####, Facsimile: 212 ###-###-####, or such other address as the Fiscal Agent shall specify to the Indenture Trustee in writing.

     The obligations of MBIA under this Policy are irrevocable, primary, absolute and unconditional (except as expressly provided herein) and neither the failure of the Trust, the Indenture Trustee, the Owner Trustee, the Trust Agent, the Seller, the Servicer or any other

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person to perform any covenant or obligation in favor of MBIA (or otherwise), nor the failure or omission to make a demand permitted hereunder, nor the commencement of any bankruptcy, debtor or other insolvency proceeding by or against the Trust, the Indenture Trustee, the Owner Trustee, the Trust Agent, the Seller, the Servicer or any other person shall in any way affect or limit MBIA’s obligations under this Policy. If a successful action or proceeding to enforce this Policy is brought by the Indenture Trustee, the Indenture Trustee shall be entitled to recover from MBIA costs and expenses reasonably incurred, including without limitation reasonable fees and expenses of counsel.

     This Policy and the obligations of MBIA hereunder shall terminate on the date (the “Termination Date”) that is ninety one (91) days following the earlier of (a) the latest Final Scheduled Distribution Date and (b) the date on which all amounts required to be paid to the Owners have been paid in full, provided, that, if any Insolvency Proceeding is existing by or against the Trust, the Seller or Onyx during such ninety-one day period, then this Policy and MBIA’s obligations hereunder shall terminate on the date of the conclusion or dismissal of such Insolvency Proceeding without continuing jurisdiction by the court in such Insolvency Proceeding, provided, further that, and notwithstanding anything herein to the contrary, this Policy shall not terminate prior to the date on which MBIA has made all payments required to be made under the terms of this Policy in respect of Avoided Payments.

     All payments made hereunder by MBIA shall be made with MBIA’s own funds. The payment by MBIA to the Indenture Trustee of any amount guaranteed by the first paragraph of this Policy, and the payment by MBIA of any Avoided Payment shall constitute “payments” for all purposes under this Policy. In no event shall any payment be made under this Policy on account of (a) the failure of the Indenture Trustee to deliver the proceeds of any such payment to any Owner or (b) the failure of any such Owner to claim any such proceeds from the Indenture Trustee.

     This Policy is not covered by the property/casualty insurance fund specified in Article Seventy-Six of the New York State insurance law.

     This Policy sets forth in full the undertaking of MBIA, and shall not, except with the prior written consent of the Indenture Trustee or otherwise in accordance with the express terms hereof, be modified, altered or affected by any other agreement or instrument, including any modification or amendment thereto and may not be canceled or revoked by MBIA prior to the Termination Date. The Premium on this Policy is not refundable for any reason.

     This Policy shall be returned to MBIA by the Indenture Trustee on the Termination Date.

THIS POLICY SHALL BE CONSTRUED, AND THE OBLIGATIONS, RIGHTS AND

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REMEDIES OF THE PARTIES HEREUNDER SHALL BE DETERMINED, IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK, WITHOUT REGARD TO CONFLICT OF LAWS PRINCIPLES OR THE APPLICATION OF THE LAWS OF ANY OTHER JURISDICTION.

     IN WITNESS WHEREOF, MBIA has caused this Policy to be executed on the date first written above.

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Exhibit A to Financial Guarantee Insurance Policy, Number 41233

MBIA Insurance Corporation
113 King Street
Armonk, New York 10504
Attention: Insured Portfolio Management,
Structured Finance

NOTICE FOR PAYMENT

UNDER FINANCIAL GUARANTEE INSURANCE POLICY NUMBER 41233

Citibank, N.A., as indenture trustee (the “Indenture Trustee”), hereby certifies to MBIA Insurance Corporation (“MBIA”) with reference to that certain Financial Guarantee Insurance Policy, Number 41233, dated May 16, 2003 (the “Policy”), issued by MBIA in favor of the Indenture Trustee under the Indenture, dated as of May 1, 2003 between Onyx Acceptance Owner Trust 2003-B and the Indenture Trustee as follows:

     1. The Indenture Trustee is the Indenture Trustee under the Indenture and the Beneficiary under the Policy.

     2. The Indenture Trustee is entitled to make a demand under the Policy [pursuant to Section 4.02(c) of the Sale and Servicing Agreement] [in connection with an Avoided Payment as defined in the Policy].

     [For a Notice for Payment in respect of a Distribution Date use the following paragraphs 3, 4 and 5.]

     3. This notice relates to the [insert date] Distribution Date. The amount claimed under the Policy, as specified to the Indenture Trustee by the Servicer, for such Distribution Date is $   . The amount demanded by this notice does not exceed amounts permitted to be drawn under the Policy.

     4. The Indenture Trustee demands payment of $   which is an amount equal to the Deficiency Amount for such Distribution Date.

     5. The amount demanded is to be paid in immediately available funds to the Collection Account at    , account number    .

     [For a Notice for Payment in respect of an Avoided Payment use the following paragraphs 3 and 4.]

     3. The Trustee hereby represents and warrants, based upon information available to it, that (i) the amount entitled to be drawn under the Policy on the date hereof in respect of

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Avoided Payments is the amount paid or to be paid simultaneously with such draw on the Policy, by all Noteholders [$ ] (the “Avoided Payment Amount”), (ii) each Noteholder with respect to which the drawing is being made under the Policy has paid or simultaneously with such draw on the Policy will pay such Avoided Payment, and (iii) the documents required by the Policy to be delivered in connection with such Avoided Payment and Avoided Payment Amount have previously been presented to MBIA or are attached hereto.

     4. The amount demanded is to be paid in immediately available funds by wire transfer to [ ].

     [For a Notice for Payment relating to both an Avoided Payment and a Distribution Date, use the following paragraphs 3, 4, 5 and 6.]

     3. This notice relates to the [insert date] Distribution Date. The amount claimed under the Policy, as specified to the Indenture Trustee by the Servicer, for such Distribution Date is $   . The amount demanded by this notice does not exceed amounts permitted to be drawn under the Policy.

     4. The Indenture Trustee demands payment of $   which is an amount equal to the Deficiency Amount for such Distribution Date.

     5. The Indenture Trustee hereby represents and warrants, based upon information available to it, that (i) the amount entitled to be drawn under the Policy on the date hereof in respect of Avoided Payments is the amount paid or to be paid simultaneously with such draw on the Policy, by all Noteholders [$ ] (the “Avoided Payment Amount”), and (ii) the documents required by the Policy to be delivered in connection with such Avoided Payment and Avoided Payment Amount have previously been presented to MBIA or are attached hereto.

     6. The amount demanded is to be paid in immediately available funds by wire transfer to [ ].

     Capitalized terms used herein and not otherwise defined herein shall have the meanings assigned to them in the Policy.

     Any Person Who Knowingly And With Intent To Defraud Any Insurance Company Or Other Person Files An Application For Insurance Or Statement Of Claim Containing Any Materially False Information, Or Conceals For The Purpose Of Misleading Information Concerning Any Fact Material Thereof, Commits A Fraudulent Insurance Act, Which Is A Crime, And Shall Also Be Subject To A Civil Penalty Not To Exceed Five Thousand Dollars And The Stated Value Of The Claim For Each Such Violation.

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     IN WITNESS WHEREOF, this notice has been executed this    day of    ,    .

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Exhibit B to Financial Guarantee Insurance Policy, Number 41233

Form of Assignment

Reference is made to the Financial Guarantee Insurance Policy No. 41233, dated May 16, 2003, (the “Policy”) issued by MBIA Insurance Corporation (“MBIA”) relating to the $400,000,000 Onyx Acceptance Owner Trust 2003-B 1.25% Auto Loan Backed Notes, Class A-1, 1.37% Auto Loan Backed Notes, Class A-2, 1.77% Auto Loan Backed Notes, Class A-3, and 2.45% Auto Loan Backed Notes, Class A-4. Unless otherwise defined herein, capitalized terms used in this Assignment shall have the meanings assigned thereto in the Policy as incorporated by reference therein. In connection with the Avoided Payment of [$       ] paid by the undersigned (the “Holder”) on [         ] and the payment by MBIA in respect of such Avoided Payment pursuant to the Policy, the Holder hereby irrevocably and unconditionally, without recourse, representation or warranty (except as provided below), sells, assigns, transfers, conveys and delivers all of such Holder’s rights, title and interest in and to any rights or claims, whether accrued, contingent or otherwise, which the Holder now has or may hereafter acquire, against any person relating to, arising out of or in connection with such Avoided Payment. The Holder represents and warrants that such claims and rights are free and clear of any lien or encumbrance created or incurred by such Holder.

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