Muscle Cars/Trucks.

something like these;
1968 Dodge Charger
2006 Dodge Charger 5.7litre Hemi
2006 Dodge Magnum
1970 Dodge Challenger
2007 Dodge Challenger
1967 Camaro SS
1970 Boss Mustang 302
1972 Mach 1 Mustang
1971 Hemi 'Cuda
2006 Dodge Ram SRT10/8

even a Nascar for the Oval tracks!
and OR a funnycar/Jet car for the drag strips. that would be awesome!!