Enter one of the following cheats at the main menu. If you entered the code correctly, you will hear a sound.
Then the corresponding code will be unlocked on the cheats screen.

Invincible
Quickly press L2(2), R2(2), L2, R2, L2, L1, R2, R1, L2, L1(2).

No police
Quickly press L1, L2, R1(4), L2(2), R1(2), L1(2), R2.

Rear wheel steering
Quickly press R1(3), R2, L2, R1, R2, L2, L1, R2, R1, L2, L1.

Long suspension
Quickly press R2, L2, R1, R2, L2, L1, R2(2), L2(2), L1, R2, R1.

Mini cars
Quickly press R1, R2, R1, R2, L1, L2, R1, R2, L1, R1, L2(3). Note: The collision detection will still behave as if the cars were normal size.

Upside-down screen
Quickly press R2(2), R1, L2, L1, R2, L2, L1, R2(2), L2, R2, L1.

View credits
Quickly press L1, L2, R1, R2, L1, R1, R2, L2, R1, R2, L1, L2, R1.