=>10 Free Cars: When starting the game, press R+SELECT+START simultaneously.
Let the time run out but don't crash. You will receive ten cars.
=>Super Auto: Hold A+B+SELECT+R and press START on the title screen for 10
cars and all the weapons. When your game time runs out you will receive the
eight extra cars.
=>Secret Route: After the red weapons truck drops your car off on the side of
the road, move further onto the shoulder rather than back onto the road. If
you drive off road far enough you will be driving on a black section; while
on this black section, you will begin collecting points, as if you were
driving on the road itself. If you drive at top speed, nothing can kill you.
However, please note that you can't return to the forest section of the
shoulder unless the road itself covers most of the screen and there is only
a small bit of brush shoulder visible.