Roadkill cheats and cheat codes for Gamecube

Cheat Codes:
Pause the game play and highlight the "Map" option. Then, press the
following button cheats. The sound of an engine will confirm,
if the typed codes are accepted.

Effect - Code
Decrease RIOT level - Y, X, A, B, Y, X, A, B, Down
Extra money - Y, X, Y, X, B, A, B, A, Down, Up
Increase RIOT level - Y, X, A, B, Y, X, A, B, Up
Infinite ammunition - Y, B, B, X, Y, B, B, X
Powerups respawn immediately - Y, A, A, Y, B, X, X, B, A, B, X, Y
Restore health - B, X, B, X, B, X, B, X
Tornado - Y, X, A, B, B, A, X, Y
Unlock all Vehicles - Up, Down, Up, Down, Y, A, Y, A, B, X, X, B

Pop a wheelie:
Find a short hill then hold Down and jump it.