Press "Pause" and type following cheat, then unpause the game:

Cheat Code - Granted effect

SLFILLUP - Fills your fuel
SLRECOVER - Turns you back to road
SLTURBINE - Unknown effect
SLALLCHEATS - Apply all cheats
SLLOTTERY - Give money and license
SLREPAIR - Repairs your car
SLROADS - Opens all your map covered roads
SLMAP - Opens whole map

If you happen to know what "SLTURBINE" does, please inform us here.