Master Code
Press Up, Down, Left, Right while the game is loading and you can read your "mission". A message will appear in the bottom right corner to confirm correct code entry. All secret options will be unlocked. Alternately, press Up, Down, Left, Right, A.

Disable Opponent AI
Press Left(2), Down, B while the game is loading and you can read your "mission". The message "Kill AI" will appear in the bottom right corner to confirm correct code entry. Alternately, press Left(2), A.

Opponents Only Attack You
Press Down, Up, Right, B while the game is loading and you can read your "mission". The message "Bot Gang Up" will appear in the bottom right corner to confirm correct code entry. Alternately, press Down, Up, A.

Unlimited Nitros
Press Right, Left, Down, B while the game is loading and you can read your "mission". The message "Infinite Nitros" will appear in the bottom right corner to confirm correct code entry. Alternately, press Right, Left, A.

No Nitros
Press Right, Left(2), A while the game is loading and you can read your "mission".

Jumping Car
Press Left, Right, Up, B while the game is loading and you can read your "mission". The message "Jumps" will appear in the bottom right corner to confirm correct code entry. Press Y during game play to jump. Alternately, press Y, Left, Right, A.

Other Codes
When the game is loading and you can read your "mission" randomly press buttons (Left Analog-stick, L, R, A, B, X, Y, White, Black) and you just may unlock a cheat message at the bottom left corner of the screen. Some examples include Kill All (All bot cars are disabled), Bot Gang Up (Bot cars always pile up), Monster Tires (self-explanatory), and Tiny Cars (RC cars).

More Damage
If you are doing anything offensive, use nitro and slam into enemies whenever possible for a boost in points immediately at the beginning. If a car is smoking and missing a door, hood, or something else, either nitro into it or hit your handbrake. Press the Analog-stick Left or Right, and slide into your enemy.

Winning
If your health is low (flashing red) and you are winning with a good lead with little time left, start going in circles and allow the timer to run out.