GMAC Financial Services Exercises Option to Purchase Capital Auto Receivables Asset Trust 2005-SN1

DETROIT, April 4, 2008 -- GMAC Financial Services today announced that it will exercise its option to purchase the remainder of Capital Auto Receivables Asset Trust (CARAT) 2005-SN1 on April 15, 2008. This will result in a termination of all of the outstanding CARAT 2005-SN1 Class B-1, B-2, and C asset backed notes.

The Class B-1 and B-2 notes will be purchased at $1,000 per $1,000 face amount, plus accrued interest from March 17, 2008. A total of $10.0 million Class B-1 4.830 percent asset backed notes, and $70.0 million Class B-2 Libor + 0.750 percent asset backed notes were sold to the public in April 2005, of which $6,185,994.24 Class B-1 asset backed notes and $43,301,959.69 Class B-2 asset backed notes remain outstanding.

The Class C notes will be purchased at $1,000 per $1,000 face amount, plus accrued interest from March 17, 2008. A total of $70.0 million Class C Libor + 1.250 percent asset backed notes were sold to the public in April 2005.

The notes may be presented and surrendered for payment to Citibank N.A., Agency & Trust Services, 111 Wall Street -- 15th Floor, New York, NY 10005. Interest on the notes will cease to accrue on and after April 15, 2008.

About GMAC Financial Services

GMAC Financial Services is a global, diversified financial services company that operates in approximately 40 countries in automotive finance, real estate finance, insurance and commercial finance businesses. GMAC was established in 1919 and employs approximately 26,700 people worldwide. For more information, go to www.gmacfs.com .