Once your on the main menu, choose "Extras", then "Cheats". type in codes and click the checkmark. A message will appear telling you that you've unlocked a new car part. To equip the new car parts, go onto story mode and go to the garage and put it on your car.
|Password||What it does|
|z74hsv||Unlocks Butterflies (wheels)|
|36mj5v||Unlocks Hoistein (Hood Ornament)|
|k4c2sn||Unlocks Mega Spoiler (Rear Accessory)|
so if you are having trouble racing because you are being bumped around, i might want to advise you to get a bigger car. the perfect size is actually medium. but if you like being large and in charge, get a large car but you have to watch out for the handling. try to control the weight of the car too. if its to heavy, it will drift more. you don't want to be too fast because you will loose control easier.
If you are in about 6,7, or 8 place and you get one of those alien spaceship things that picks you up and carry you quite a ways, see if you can get to about 1,2,or 3rd place with out the spaceship and then use it and you'll get a good lead. but if you are really REALLY far behind, go ahead and use the spaceship to get into the area where the other racers are.