Complete championship mode under the "Novice" and "Expert" difficulty levels.
Complete one of the following series with the corresponding setting to enable a bonus car:
Arcade Basic series (Novice) - Porsche 959
Arcade Basic series (Expert) - Ferrari F-50
Arcade Pro series (Novice) - Ferrari 512 TR
Arcade Pro series (Expert) - Dodge Viper GTS
Normal Championship series (Novice) - Bugatti EB110 GT
Normal Championship series (Expert) - McLaren F1