The new IGN car pack for Forza 4 includes the following list of new cars for use. Two of the most interesting (to us) are the Monster Sport Suzuki SX4, the massivly-winged car designed for Pikes Peak hillclimb competition, and the Ford SVT Raptor (although we don't know why ;-)

December IGN Car Pack List

2011 Monster Sport Suzuki SX4
2011 Mazda RX-8 R3
2011 Ford F-150 SVT Raptor
1967 Chevrolet Chevelle SS-396
1977 Ford Escort RS1800
1981 Volkswagen Scirocco S
1986 Alfa Romeo Spider Quadrifoglio Verde
1988 Pontiac Fiero GT
2010 Maserati GranTurismo MC GT4
1957 Maserati 300 S

See more about the cars here: IGN-Forza4 Dec Pack

The December IGN pack will be available on Xbox LIVE starting December 6 and selling for 560 Microsoft Points (roughly $7.00 USD or 6 Euros).

If you've purchased a Forza Motorsport 4 Season Pass, the pack will be available at no additional cost. A Season Pass can be picked up through the Xbox LIVE Marketplace or participating retailers, including Best Buy and GameStop, for 2400 Microsoft Points ($29.99 USD), and gives you access to all six planned game add-on packs for Forza Motorsport 4 at 30 percent savings.