To Get the extra cars Win each track on the normal level or above in Normal and Endurance racing modes. To Get the Demon car use Racer X's Shooting Star car and win a race in Time trial mode. To get the GRX (the fastest car) use one of the Mach V cars or the Demon on the M track. You need to enter the ruins with this car. Put on your deflector and saws and look for a set of closed doors on your left after you enter the tunnel. If you are going fast enough you will break through the doors. Drive through the Ruins and hang a left and you will see the GRX car on display. Then go right and jump over the rail go through the water and you will need to jump out onto the race track. Entering this hidden cave releases the GRX. Use a memory card to save your data so the cars will be available the next time you play.

To get the extra cars without earning them, do this. At the car select screen press and hold R1 + R2 + L1 + L2 + SELECT + DOWN + TRIANGLE. Release everything, then scroll LEFT or RIGHT to view the other cars.

At the course select screen:

Night Only Race - Hold R1+R2 and press X
Day Only Race - Hold L1+L2 and press X
Dusk Only Race - Hold R1+R2+L1+L2 and press X

While racing press START, then tap RIGHT on the d-pad 5 time and LEFT on the d-pad 5 times.

Use either the Mach 5 or the Demon car. After the tunnel and a little drive, you will find something resembling a gas station. Go in it and jump through the little fence. Use the rotary saws and grip tires(or traction) to cut through. Then drive through the underwater pond and jump through the little fence.

Activate the Rotary Saws on either the Mach 5 or the Demon, then use the Auto Jacks to attack the sign.