Wacky races

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.
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 vehicle abilities
Select the "Cheats" option at the main menu. Enter "BARGAINBASEMENT" 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.

Game Shark Codes

Infinite Tokens P1 Battle Arena D2788109
0000000A
Infinite Retries Wacky Cup F02DD617
00000005
Always Have 10 Muttleys 8E938D7E
000003FF