Enter the following codes at the main menu
Effect cheat
Arcade-style beat the heat mode ,press Up, Down, Left, Right, R1, Left, Right.
Hardcore realism mode press Up, Down, Left, Right, R1, Up, Down.
Remove replay text , press Up, Down, Left, Right, R1, Down, Up. Start a replay, then press Circle
Unknown press Up, Down, Left, Right, R1, Right, Left.
View credits press Up, Down, Left, Right, R1, Up(2)
Paint Balls
press Up, Down, Left, Right, R1, Up(2) at the "Race Day" screen in single race or head-to-head mode, .Press your horn to fire paintballs.
Another way to enter in this code is to select practice mode and press Up, Down, Left, Right, R1, Down(2) to enable paintballs.
Unlock Richard Petty
complete all Heat challenges with a bronze or higher rating