If you are playing on PC and looking for a save game or mod to access this car, this is likely what you are looking for. The mod is the gold standard for Carbon players.
Trusted sources include sites like NFSAddons or NFS-Cars . Installation: Nfs Carbon Bmw M3 Gtr Save Game
: Offers saves for PC, Xbox 360, and GameCube with 100% unlocks. If you are playing on PC and looking
Always before swapping files. If the game crashes on startup, it's likely a version mismatch between the save and your game (v1.2 vs v1.4). Nfs Carbon Bmw M3 Gtr Save Game