Enable the "Guns and rockets" code. Select the motorcycle, if available. When you are about to begin a race, start to burn out. Shift yourself towards another racer while still burning out by using the Left Analog-stick. Press R3 to fire a missile at an opponent. You should both explode. However when you recover, your bike will be riding on its own. Note: Your damage meter will be very high; if you crash and recover, your driver will be back.