There's a good article on e-kmi.com about how parents should act while at the kart track here: http://www.e-kmi.com/article.cfm?article_id=1581 .... I couldn't agree more with the points they raise.

It's great to be at the track and to be supportive by being the mechanic/coach/etc.... but please keep a smile on your face and don't go shouting at officials or anyone else at the track. A little sensible conversation is ok but more than that and you have to take a deep breath and sit down for a while. It's funny how it's usually only the parent that is pissed off about something - the kid couldn't care less he's over playing with his mates.