GRID Cheat codes for PC

Bonus cars:

At the main menu, select "Options", "Bonus Codes", then "Enter Code". Then, enter one of the following codes to unlock the corresponding car in Grid World and Raceday mode. Note: You must have $40,000 to start your own team to get the option to view and test drive the bonus cars.
Drift cars

Enter "TUN58396" as a code to unlock drift cars.
Stage 1 classic muscle cars

Enter "MUS59279" as a code to unlock the Stage 1 classic muscle cars.
Buchbinder 320si Livery

Enter "F93857372" as a code to unlock the Buchbinder 320si Livery.
GameStation BMW 320si Livery

Enter "G29782655" as a code to unlock the GameStation BMW 320si Livery.
Micromania Pagani Zonda R Livery

Enter "M38572343" as a code to unlock the Micromania Pagani Zonda R Livery.
Play.com Aston Martin DBR9 Livery

Enter "P47203845" as a code to unlock the Play.com Aston Martin DBR9 Livery.
Completion bonuses

Successfully complete the game with all 51 Gold trophies to unlock all cheats and special cars. You will also unlock a final Head-to-Head race with Ravenwest consisting of three laps around Circuit de la Sarthe that must be done on the Extreme difficulty. The race is worth $20 million and also awards you bonus cars, allowing you to have a total of 47 cars in your garage.
Ninja mode

Win all trophies and complete all Head-to-Head races in Grid World to unlock the Ninja difficulty.
Global license

Unlock all of the other regional licenses, then earn 1 million Global Points to get the Global license. Note: All other licenses that have not been acquired yet will also become unlocked.