Pause the game in single player mode. Then, enter the "Sound" option, highlight the "FX Volume" selection, and press L1 + L2.

Faster engine

Select multi-player mode. Then at the track selection screen, press X + Square + Triangle + Circle. If the code was entered in correctly, an engine will be displayed at the bottom of the screen.

Jumping cars

Select multi-player mode and select a track and car. Then when the countdown that marks the start of the race begins, press Circle + Left.

Night racing

While you are at the track selection screen, hold L1 + L2 + R1 + R2 until headlights appear in front of the car. If the code was entered in correctly, a new symbol will appear on the track.

Upside down tracks

While you are at the track selection screen, press L1 + R1 + X + Down. If the code was entered in correctly, an arrow will appear at the bottom of the screen.

Reversed tracks

Choose a track and press Select. Then, quickly hold X + Square as the cars enter the tunnel. While continuing to hold those buttons, press Left or Right. If the code was entered in correctly, the cars will turn around and enter the tunnel in reverse. Alternatively, press L2 + R2 + X + Down at the track selection screen. If the code was entered in correctly, an arrow will appear.