Shoot paintballs
up,down,left,right, R1,up,up

Shooting Tires
At the race day screen push UP,DOWN,LEFT,RIGHT,R1,UP,UP. It will take you to the race and when you push the D-pad up tires will shoot out of the front of your car.

Hardcore realism mode
Get a 100 point rating on a track to unlock the hardcore realism mode option for that track.

Race as Richard Petty
Complete all Heat challenges with a bronze or higher rating to unlock Richard Petty.