A known issue: If you unlock every car in the game via the editor, your "My Cars" menu may lag. The game tries to render 100+ car models simultaneously. Solution: Only unlock the 20 cars you actually drive.
Now, start your engine, load your edited profile, and take that Works-converted Zonda R around Spa-Francorchamps. You’ve earned it (metaphorically, at least).
You will see a file named something like: NFS Shift 2.savedata or a string of numbers and letters.
Safety and legal considerations