There was a video of someone playing a rally racing game floating around not too long ago. It was pretty cool. It doesn't look like much, but it is not something you can just get at the hardware store.
We're talking logic and controls for the actuators...programming to interfact the game to the controls....
Think of it as a flight simulator ... for the car junkie with spare change...
I'd love to have one...but I'd have to sell one of the real cars to get it