At the main menu, activate the following cheats by entering the corresponding codes

CHEAT FUNCTION - CHEAT CODE
All cars - ineedmorecars
All tracks - ineedmoremaps
Bonus track - fonekart
Faster race - speedracer
Low gravity - manonthemoon
High gravity - glued
Generate tracks - terraformers
Slippery track - greasy
Small wheels - gokartz
Large wheels - bigfootz
Big heads - bigheadz
Big hands and feet - boxerz

While playing the game, activate the following cheats by entering the corresponding codes

CHEAT FUNCTION - CHEAT CODE
Toggle clouds - CTRL + H
Toggle fog - CTRL + F
Toggle exterior mirrors - CTRL + N
Toggle mirror - CTRL + M
Toggle interface - CTRL + I
Increase view distance - CTRL + J
Decrease view distance - CTRL + K
View frame rate and ping times - CTRL + Z
View coordinates - CTRL + C
Alternate map views - CTRL + T

Activate the following cheats by starting the game with the corresponding command line parameters:

CHEAT FUNCTION - COMMAND LINE PARAMETER
No FMV sequences - nomovie
Run game in window - nofullscreen
Disable mouse in the game - nomouse
Allow ALT + TAB Windows switching - nomutox