Master cheat:

Enter your driver's name as Nosliw to get all of the cars, tracks and paint jobs.

New Paint Job:

5 hours of gameplay will give you the medal pursuit (new paint jobs).

Faster Mercedes:

Enter Reki as player name to unlock a faster Mercedes

Cool Cars:

Earn 1000 Kudos and get VW Bug. Earn 25000 Kudos and get Panoz Esperante.

Unlock the Delfino Feroce:

Earn 75,000 to receive the Delfino Feroce.

Unlock the Lotus Exige:

Earn 50,000 to receive the Lotus Exige.

New Helmet:

After you play for one hour you get a new driver's helmet.

Ferrari F-50:

Get 200,000 kudos to unlock the Ferrari F-50.

Free Roam in Time Attack Mode:

Win a silver or gold medal in all parts of kudos challenge mode for a city. Select time attack mode and a "Free Roam" option will be unlocked for that city