MotorStorm Codes -

Cheat Mode
To enter the code, simply hold down all the buttons as well as pushing the analog sticks down. You'll also need to move them in the direction shown in (). Enter the Big Head code whilst paused, and the Everything code on the main menu. You will hear a sound if done correctly:

Pause the game, then hold + + + + (whilst pushed right)+ (whilst pushed left) - Big Head (ATVs and Bikes)
At main menu hold + + + + (whilst pushed up)+ (whilst pushed down) - Unlock Everything
Hold down + + + + (While holding right), (While holding left) - Singleplayer Mirror Mode

Extra boost
Use the following trick for an extra boost that can help you to victory at the end of a race . When you are coming up on the finish line, have your boost meter almost all the way full. When the finish line is fairly close, throw on the boost. Do not stop holding on the boost and your car will began to heat up. After the meter is all the way to the end your car will explode, launching you a good distance forward at an extremely high speed.

Going faster
To make yourself go faster in any vehicle while driving (you must let your boost charge), keep tapping X. This will make any vehicle go faster and not use boost.

Unlimited Boost - No Overheat
When in a race, keep tapping the Boost button. You will boost without overheating.