I've dreamed of such a thing for years. If the physics were spot on, and perhaps the roads within the game had destinations at the end. e.g You have to drive to get to a race track , as well as all cars premium, I would accept it. Until the technology is good enough for a driving simulator like GT5 to be merged into a highly detailed virtual world, then I'm not to sure about it. TDU probably did this whole idea best, just with rubbish physics.