Lexus LFA, stock exhaust
Dodge Viper ACR, sports exhaust. Probably the best noise in the game.
VW SambaBus, sports exhaust
Suzuki Swift Sport, fully tuned except stock exhaust, very high revs
Aston Martin V12 Vantage, stock exhaust
Ford Focus ST, 2000-4000rpm, stock exhaust
Infiniti Coupé Concept, up to about 6000rpm, stock exhaust
Mercedes-Benz SLS AMG, stock exhaust
Dodge Ram 1500, stock exhaust
Ford Mark IV Race Car
Formula Gran Turismo
Nissan R92CP Race Car
and...
No road cars with racing exhausts. The majority sound godawful.