Burnout

[final kaoss]

All racers

Press R2(3), L1, Triangle, L2(3), R1, Square at the title screen.

[final kaoss]

Bus

Beat this car in Face off 4.

[final kaoss]

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.

[final kaoss]

Face Off option

Successfully complete championship mode once to unlock face off mode against the Roadster.

[final kaoss]

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.

[final kaoss]

Roadster

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

[final kaoss]

Saloon GT

Beat this car in Face Off 3 to unlock the Saloon GT.

[final kaoss]

Towtruck

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