Reversed tracks:
Complete championship mode under the "Novice" and "Expert"
difficulty levels.

Hidden cars:
Complete one of the following series with the corresponding
setting to enable a bonus car.

Porsche 959              Arcade Basic series (Novice)
Ferrari 512TR            Arcade Pro series (Novice)
Bugatti EB110 GT Normal  Championship series (Novice)
Ferrari F-50             Arcade Basic series (Expert)
Dodge Viper GTS Arcade   Pro series (Expert)
McLaren F1               Normal Championship series (Expert)