Start a race, and at the Enter Name screen, input the following names to activate the cheats. If you entered the name correctly, a confirming voice will say, "Cheat mode enabled."
Note: The following cheats work only in Single Race and Time Trial modes.
Access All Tracks: JHAMMO
Disable Collision Detection: CMNOHITS
Go-Kart Mode: CMCHUN
Helicopter View: CMCOPTER
Lock Tracks Back Up: CMLOCK
Low-Gravity Mode: CMLOGRAV
"Micro Machines" Mode: CMMICRO
Multicolored Fog: CMDISCO
Race as a Tank: CMGARAGE
Rain Falls from the Ground Up: CMRAINUP
Starry Sky Mode: CMSTARS
TOCA Showdown (Mirrored Championship): PATSCREEM
Turbo Mode: XBOOSTME
Volcano Track: CMDISCO