Old thread, but GRID was an easy game to beat on normal settings. I'm sure if I jacked up the difficulty any more it would be much tougher. I've unlocked all the cars, all the trophies, and all I can do now is either play online or do those mini races.
This game lacks replay value, for me at least. I'll probably uninstall once a good game comes out for PC.. it's just too bad GOW2 won't be ported to PC, and Far Cry 2+Crysis Warhead have SecuROM. Looks like I'll be waiting a long time.