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.