Just a quick heads up about a racing sim you may or may not have heard about. Seems a lot more realistic physics wise than most racers i have played and has a great mature community where the emphasis is on good clean racing. Some footage of an STCC event using LFS to whet your whistles:
LFS is currently streets ahead on that front and is the driving sim of choice in Europe it seems. Certainly it's what we use over at dMw at the moment.