Unlock Everything - At the Mode Select screen press L, Z, R, C-Up, C-Down, C-Left, C-Right, then Start. (A chime will ring out accepting this powerful cheat.)

Tiny Cars - At the Machine Select screen press and hold L and R then press Left C and Down C to shrink the vehicles.

Change Colours - At the Adjust Your Machine screen, press the R button repeatedly to scroll through the various paint jobs.