Successfully complete the indicated task to unlock the corresponding car:

Acura NSX: Defeat your Rival.
Aston Martin DBR9: Unknown.
Audi R8: Unknown.
BMW M3 E46: Defeat your Rival.
BMW M3 GT2: Reach 100% for all Driver points (Drift, Grip, Precision, and Speed).
Bugatti Veyron 16.4: Successfully complete the game.
Chevrolet Corvette Z06: Defeat your Rival.
Dodge Challenger Concept: Unknown.
Dodge Charger SRT8 Super Bee: Unknown.
Dodge Viper SRT10: Defeat your Rival.
Ford GT: Unknown.
Honda S2000: Defeat your Rival.
Koenigsegg CCX: Defeat your Rival.
Lamborghini Gallardo LP560-4: Unknown.
Lamborghini Murcielago LP640: Defeat your Rival.
Lotus Exige S: Unknown.
Mercedes Benz McLaren SLR 722 Edition: Unknown.
Mitsubishi Lancer Evolution: Defeat your Rival.
Nissan 350Z (Z34): Unknown.
Nissan GT-R (R35): Defeat your Rival.
Pagani Zonda F: Unknown.
Porsche 911 GT3 RS: Defeat your Rival.
Porsche Carrera GT: Unknown.
Porsche Cayman S: Unknown.
Shelby 1967 GT500: Unknown.
Volkswagen Sirocco: Unknown.