AMENDING AGREEMENT NO. 4

Exhibit 10.50(d)

Execution Copy

AMENDING AGREEMENT NO. 4

THIS AGREEMENT made as of the 21^st day of November, 2007,

B E T W E E N:

AVISCAR INC.,

a corporation incorporated under the laws of Canada,

(hereinafter called the “Avis General Partner”),

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BUDGETCAR INC.,

a corporation existing under the laws of Canada,

(hereinafter called the “Budget General Partner”),

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BNY TRUST COMPANY OF CANADA,

a trust company incorporated under the laws of Canada and registered to

carry on the business of a trust company in each of the provinces of

Canada, in its capacity as trustee of STARS TRUST, a trust established

under the laws of the Province of Ontario,

(hereinafter called the “STARS Limited Partner”),

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MONTREAL TRUST COMPANY OF CANADA,

a trust company incorporated under the laws of Canada and registered to

carry on the business of a trust company in each of the provinces in

Canada, in its capacity as trustee of BAY STREET FUNDING TRUST,

a trust established under the laws of the Province of Ontario,

(hereinafter called the “Bay Street Limited Partner”).

WHEREAS the Avis General Partner, the Budget General Partner, the STARS Limited Partner and the Bay Street Limited Partner have entered into a fourth amended and restated limited partnership agreement made as of the 20th day of April, 2005, as amended by amending agreements between the parties dated October 11, 2005, July 7, 2006 and December 11, 2006 (collectively, the “Limited Partnership Agreement”);

AND WHEREAS the Avis General Partner, the Budget General Partner, the STARS Limited Partner and the Bay Street Limited Partner wish to amend the Limited Partnership Agreement;

NOW THEREFORE THIS AGREEMENT WITNESSETH that in consideration of the premises and covenants and agreements of the parties herein contained and for other good and valuable consideration (the receipt and sufficiency of which are hereby acknowledged by each of the parties), the parties hereby covenant and agree as follows:

““Available Call Amount” means, in respect of a Limited Partner, the amount by which (a) the sum of $300,000,000 and the aggregate Principal Amount of Bonds issued by such Limited Partner outstanding at such time exceeds (b) the balance of the Limited Partner’s Capital Account of such Limited Partner at such time; provided that on and after the occurrence of a Funding Termination Event for such Limited Partner, the Available Call Amount for such Limited Partner shall be deemed to be zero;”.

“(b) The balance of each Limited Partner’s Capital Account shall not at any time exceed an amount equal to the sum of $300,000,000 plus the aggregate Principal Amount of Bonds issued and outstanding by such Limited Partner at the time of determination.”.

Any reference to the Limited Partnership Agreement made in any documents delivered pursuant thereto or in connection therewith shall be deemed to refer to the Limited Partnership Agreement as amended or supplemented from time to time.

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IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be executed by their authorized signatories thereunto duly authorized, as of the date first above written.

The undersigned hereby acknowledges notice of and consents to the foregoing amendments to the Limited Partnership Agreement.

DATED this 21st day of November, 2007.