Reverse track:
To play on a reverse track, drive forward at the starting point until you get to fifth gear. Then, make a "U" turn and drive towards the wall. If done correctly, you will hit sixth gear and the wall will disappear. The track will now be in reverse.

Bonus cars:
Play ten multi-player races using a single cartridge to unlock the 00-Agent car. Keep playing in multi-player mode to continue unlocking bonus cars, in the following order: Red Shirt Rage, Pooka, Caddy Car, Galaga '88, Shy Guy, and Mario Racing.

To unlock all bonus cars in the game, win all the Platinum GP races.