Pause the game during a race, then type:

Code             Result 
machthree    600 km/h super car 
impact           Unlimited ammo in deathmatch mode 
clementine    Free choice in starting league 
overkill          Enable weapon mode in championship 
mccoy          Animated switches in menus 
likepamela     Tuning phase 5 for all systems 
liselotte         All additional systems at 99 
nalice            All cars 
alloff             Cheat mode off