Endless time and continues:
Press Up, Down, Up, Down, Left, Right, Left, Right, Up, Left, Down, Right at the main menu.

Stage skip:
Go to the main menu and press Up, Down, Up, Down, Left, Right, Left, Right, Down, Left, Up, Right.

All cities:
At the main menu press L1, L1, R1.

All cars:
Press L2, R2, L2, R2 at the main menu.

All bonus levels:
Select the main menu and press L1, R1, L2, R2.

Win single player game:
Press L2, R2, L1, R1 at the main menu.

Alternate paint job:
At the main menu, press Down, Square, Down, R1, Right(2), Up, Left, Circle(2), L2, L1 to change the paint job of your car when you begin a game.

Motion blur mode:
At the main menu, press Up, Left, Circle, Down, Right, Square, Up, Down, Left, Right, Circle, Square to unlock a "Motion Blur" selection in the options menu.

The Geeze car:
Collect all coins in Rome level 1 to unlock The Geeze car.

P-nut car:
Collect all coins in Rome level 2 to unlock the P-nut car.

Froggy car:
Collect all coins in Rome level 3 to unlock the Froggy car.

Super Genius car:
Collect all coins in London level 1 to unlock the Super Genius car.

Turtle car:
Collect all coins in London level 2 to unlock the Turtle car.

Ricochet car:
Collect all coins in London level 3 to unlock the Ricochet car.

Fang car:
Collect all coins in London level 4 to unlock the Fang car.

Road Shark car:
Collect all coins in London level 5 to unlock the Road Shark car.

Portabello car:
Collect all coins in Tokyo level 1 to unlock the Portabello car.

Street Eagle car:
Collect all coins in Tokyo level 2 to unlock the Street Eagle car.

Black Widow car:
Collect all coins in Tokyo level 3 to unlock the Black Widow car.