All vehicle abilities:
Select the "Cheats" option at the main menu. Enter BARGAINBASEMENT as a
code, then enable that cheat at the "Code Collection" screen. 

All cars:
Select the "Cheats" option at the main menu. Enter WACKYSPOILERS as a code,
then enable that cheat at the "Code Collection" screen. 

All tracks and Bosses:
Select the "Cheats" option at the main menu. Enter WACKYGIVEAWAY as a code,
then enable that cheat at the "Code Collection" screen. 

Hard as nails mode:
Select the "Cheats" option at the main menu. Enter CRACKEDNAILS as a code,
then enable that cheat at the "Code Collection" screen.