Enter in cheat Menu:

All Cars - YAYCARS
Hard Story Mode - CHMPION
Fast Start - IMSPEED
Unlocks all tracks and mini games - MATTL66
Unlocks all tracks and mini games - IF900HP
Inf Boost - VROOOOM
Unlocks Art - CONC3PT
Unlocks Movie Clips - WATCHIT
unknown - R4MONE
Unlock Master's Speedy Circiut and Master's Countdown Cleanup - TRGTEXC