Burnout Available Cheats:

Ending bonuses
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.

Bus
Defeat the bus in Face Off 4 to unlock it.

Roadster
Defeat the Roadster in Face Off mode to unlock it and another face off race against another car.

Saloon GT
Defeat the Saloon GT in Face Off 3 to unlock it.

Towtruck
Play in championship mode until you unlock Face Off 2 in the special options screen. Defeat the Towtruck once to unlock it.

Quick start
Accelerate immediately before the "1" fades during the pre-race countdown to start with a slight boost in speed.

Increase boost
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.

Full bonus
Drive a perfect lap (a lap without any accidents) and your bonus will be automatically filled.

Better turns
When turning sharp corners, lightly tap the gas to turn sharper and slide less.