Here are some cheats and tips for the game High Velocity.
Hidden Cars:
At the car select screen, press Right until you reach car “F.” The
press and hold L, R, and Y. With these buttons held down, press Right
on the control pad. Now you can select a new car, “G” � the Porsche.
You can also select another hidden car, a truck, by holding down L, R,
and Y simultaneously and pressing Right again.