Uma horse
Place first on every track in a normal race within the hard difficulty setting.

Uma 2 horse
Place first using Uma on every track in a normal race within the normal difficulty setting.

Dinosaur Canyon area
Turn the car around at the starting line, then drive up the ramp that is on the right.

Daytona bonus car
Place first on every track in a normal race within the normal difficulty setting.

Drift through corner
When you want to drift though a corner, simply shift into first gear and turn the corner. When the car start's to drift a bit, shift back into third or fourth gear. This is really useful in the E corner.