All cars and tracks:
At the main menu, press Right, Right, Left, , Up, L2, L2, R1.

Different Camera Modes:
In Replay mode, press Select to change the camera color or lens.

Extra cars:
First unlock all of the cars. Choose the San Francisco Drag Race and set a new time record with the Dodge Concept Viper. Now enter the name SOUNDMAX at the high score screen. This will unlock the Jaguar XK-R "SoundMAX SPX", Jaguar XK-R "Analog Devices", and the Aston Martin DB7 "SoundMAX SPX."

Unlock London:
Win all London races in Story mode to unlock the London tracks in Single Race and Cop Chase. You'll also unlock the Chevrolet Chevelle SS 454 and Skeeter's Pontiac GTO.

Unlock Monte Carlo
Win all Monte Carlo races in Story mode to unlock the Monte Carlo tracks in Single Race and Cop Chase. You'll also unlock the Aston Martin DB7 Vantage, Chevrolet Corvette Z06, TVR Cebera Speed 12, and Ford SVT Mustang Cobra R.

Unlock Tokyo:
Win all Tokyo races in Story mode to unlock the Tokyo tracks in Single Race and Cop Chase modes. You'll also unlock the Nissan Skyline GT-R V-Spec, Dodge Charger, Subaru Impreza 22B, and Shelby Series 1.

Thanks to Revolution readers Joe Mafia, Derek Maner, Brad B., clyde, Adam, and Erich Schindler!