First go into the view so you can see the driver holding the steering wheel. Next hold down triangle for 2 seconds.
Turbo Mode
At the Options screen, hold Circle then press Up, Left, Down, Right. A new option will appear at the bottom of the screen.
Pinnacle Car
You can only do this trick in exhibition mode. Go to the Race Setup/Car Select screen and highlight the Bobby Labonte car. Then hold X then press Up, Down. Note: You will lose this car if you leave Exhibition Mode.
Machine Gun Fire
As soon as the green flag drops, go to the race statistics screen in the options menu. Hold L1, L2, R1, R2, and triangle until a motor sounds. Then release everything. To shoot, press square.
Faster Car
Go to the Car Setup Screen. Put the pressure all the way up, the wedge all the way down, the rear spoiler all the way down and the gear ratios all the way up.
EA Sports Car
Go to the Exhibition Mode. Select the Race Setup/Car select Screen and highlight the Kenny Wallace car. Hold X and press Up and Down on the D-Pad.
Paintball Mode
Pause the game during a race (after the green flag). Select Race Statistics. Press and hold R1, R1, L1, and L1 simultaneously. You should hear an engine sound. Resume the race and press Triangle to fire paintballs that destroy your opponents.