First, add the -console command-line parameter to the shortcut for your game. Open the console in-game by pressing "~" (tilde). You can then type any of the following cheats.
Code: Result:
god (1) God Mode On
god (0) God Mode Off
giveall 10,000 Coins, Max HP, Max Fuel
givemoney # Get Money
truck # Each # is a Different Truck
giveguns # Each # is a Different Gun
map (1) Reveal Map
teleport # Teleport (#=Location)