That is SO ufair!!! Your windows were up!!!
I did a track day last year in my track car (a 1989 MR2 Supercharged) at Buttonwillow. It rained... windows had to be down. That was a miserable experience!!!! I definitely would not do that to a car I care about keeping clean, such as my X3! On the other hand, your point about car control at slow speeds is well taken, as I did learn a lot that day.
While I had a track car I probably did 12 - 14 track days. The seat time was very valuable indeed! For now I think I will stick mostly to auto-x since it is much safer. I have 2 kids who depend on me and they are my priority right now. I might do a track school or two per year to keep from getting TOO rusty.
That S2000 looks like a great track car! Again, I truly appreciate the good advice! It is well taken!