While playing, hit the brakes frequently to damage them. At the repair screen, repair everything except brakes. Keep doing this untill the brakes are damaged 100%, then while playing the next level, hit your brake button and hold on for one hell of a ride.
Save the car with at least 97% damage done to the tires. When you restart the game and play using this car you will leave smoke and tire tracks from the tires everywhere you go. I have not found a practical use for this code but it is still entertaining.
This only works on stages where you can use your headlights. Save your car with at least 97% damage to the headlights. When you restart the game using this car you will see your headlights bouncing all over the stage whenever you hit a bump or rock on the road. Have fun.
If you save your car with over 97% damage done to the suspension and restart the game using this car and the "Warp Speed" code, you will be able to jump out of the screen when you hit a ramp or a log on the race track. This will only give you an advantage on about 3 tracks. You can not jump over things like houses or trees. You still have to stay in the confines of the normal race track. But it is still a fun code to play with.