At the title screen, press R2(3), L1, Triangle, L2(3), R1, Square to unlock all characters.
Successfully complete the game to unlock the Free Run mode (no vehicles on the road), Free Run Twin mode (two player Free Run), and "Credits" options.
Face off mode
Successfully complete championship mode once to unlock face off mode against the Roadster.
Defeat the bus in Face Off 4 to unlock it.
Defeat the Roadster in Face Off mode to unlock it and another face off race against another car.
Defeat the Saloon GT in Face Off 3 to unlock it.
Play in championship mode until you unlock Face Off 2 in the special options screen. Defeat the Towtruck once to unlock it.
Accelerate immediately before the "1" fades during the pre-race countdown to start with a slight boost in speed.
Drive on the wrong side of the road to keep increasing your boost. This can also be done by driving in the center of a double lane. Drive on the wrong side of the road and use the turbo when you get it. After it is gone, your turbo will either be full or half full.
Drive a perfect lap and your bonus will be automatically filled.