Here's some Carbon cheats I've happened to stumble upon. There are many saved games as well with everything unlocked if you wish as well?
here's the URL
http://www.actiontrip.com/cheats/needforspeedcarbon.phtmlCheat Codes
Type any of the following cheat codes at the 'CLICK TO CONTINUE' screen. Some codes may work if entered at the MAIN MENU screen. Note: Entering a code incorrectly will require the game to be restarted.
canyonalltheway: All Tracks
shinycarsarethebestcars: Chrome Cars
5grand5grand: Castrol Cash
friendlyheadlocksapplied: Unlimited Crew Charge
nosforeverever: Unlimited NOS
slowitdownwhenyouwant: Unlimited SpeedBreaker
givemethechargersrt8: 2006 Dodge Charger SRT8
givemethedb9: 2005 Aston Martin DB9
chasingheadlocksappliedrashtalk: Mazda Dealership
speed3foryou: Mazda Speed3
watchoutthebigtruckishere: Dump Truck in Quick Race Mode
bigredfiredrive: Firetruck in Quick Race Mode
trashtalking: Rhino in Quick Race Mode
guesswhoisback: Cross Corvette Z06 in Quick Race Mode
chasingmobile: Corvette Z06 Interceptor in Quick Race Mode
cooperlogofreeforyou: Cooper Tire Logo
pharrellvinylgogo: Pharrell Vinyl
lotsoffreevinyls: NFS Carbon Special Vinyls
lotsoffreelogos: NFS Carbon Vinyls
syntecskin: Castrol Syntec Vinyl
inthezoneskin: Autozone Vinyl