Get Faster Mercedes:
Put in Reki for the driver's name

Get New Helmets:
The more hours you play, the more helmets you unlock. Every hour you play Project Gotham, you get another.

Get New Paint:
To earn some nifty new paint jobs, rack up five hours of gameplay. That's it. Just play.

Unlock Everything:
To unlock it all in one go, enter "Nosliw" as your character name. All tracks and cars will now be at your disposal.

Unlock Lotus Exige:
To unlock the Lotus Exige, get 50,000 total Kudos.

Unlock Panoz Esperate:
To unlock the Panoz Esperate, get 25,000 Kudos.

Unlock the VW Beetle:
To get the Beetle, simply get 1000 Kudos on easy difficulty.