Various cheats
 Type these codes at the intro screen (the one that comes up
before the main menu that says "Press Enter" -- right before your
profile is loaded). If accepted, a small beep will be heard.

Cheat code: Result:
needperformance1 Unlock Performance Parts Level 1
needperformance2 Unlock Performance Parts Level 2
gimmevisual1 Unlock Visuals Level 1
gimmevisual2 Unlock Visuals Level 2
regmebaby Unknown Effect
ordermebaby Unknown Effect
regmybank Unknown Effect

Unlock Sponsor Cars
 These codes are entered the same way and will unlock SPONSOR cars
that can be selected by switching the car selection option to SPONSOR
CARS from ALL CARS (using the right/left arrows on the menu).

Cheat code: Result:
opendoors The Doors GTO
gimmechingy Chingy Navigator
tunejapantuning Japan Tuning G35
davidchoeart David Choe Corolla
shinestreetbright Shine Street Lexus IS 300
wannacapone Capone H2
wantmyd3 D3 Eclipse

Unlock Sponsor Vinyls
 These codes are entered the same way and will unlock sponsor
vinyls. These are selected under the CUSTOMIZE menu, under VINYLS.
Scroll all the way to the right and you will see SPONSOR as a
selection.

Cheat code: Result:
needmybestbuy Best Buy
goforoldspice Old Spice
gotmycingular Cingular
gottahavebk Burger King
gottaedge Edge