Go to Options and Cheat Codes, then activate the following cheats by entering the corresponding codes:

CHEAT FUNCTION - CHEAT CODE
All characters - MATTEL07
Alternate colors for all characters except Lightning McQueen - PAINTIT
Alternate colors for Lightning McQueen - NCEDUDZ
All story-mode wheel sets and Luigi's Casa Della Tires unlocked - INSTYLE
All races and mini games in Arcade mode; and all three Worlds in Story mode - PLAYALL
Unlock all bonus art for purchase - BUYTALL
Unlock all game content except most Story mode races - ALLYORS
Expert difficulty - VRYFAST
Unlimited turbo boosts - ZZOOOOM
Extreme acceleration - 0TO200X