I have run Road America several times on my pc with the old SportscarGT game. It was made available in a track pack. I can take the kink flat out and used to tell my driver when he didn't he in real life he was a girl.
Ken, if you ever make SEMA, stop by the Saleen booth. They have the most awesome and realistic sim I have ever driven. Price tag was $25k I am told. Beyond getting hit with rubber gum balls off the tires, it doesn't get any more real.