I don't see the windows closed rule on the Ford Fair website at
http://www.fordfair.co.uk/2011/02/14/track-time-rules/
though I've been on track before at FF and was told too.

If we already have to put on long clothes, it's going to be like a bloody oven in my car. Can we have the windows open a bit? I saw plenty going round with windows half-down when I was last on track.