Beating the game's 9 rivals in "One-on-One" battles awards you their unique, custom-liveried cars.
Blur originally required a GFWL login. Modern cracks (like Razor1911 or SKIDROW) bypass this. If you are using an original disc install, your save file is stored in Microsoft's cloud. for save manipulation to work. Blur Unlock All Cars Pc Code
Alternatively, use with a known table (from Fearless Cheat Engine forums) to manually set fan points to 999,999 and level to 50. Beating the game's 9 rivals in "One-on-One" battles