The question should be - will the helmet manufacturer back up their snell rating with a camera mounted to their helmet? If the answer is no, the track/sanctioning body has now taken on the liability if they allow it.
I think you should at least be able to mount it on the kart - they are awesome for track advertising also.
Im pretty sure that the "snell" rating is just the standards that the manf. needs to meet ...has nothing t do with backing up the helmet
Void of what? You're using the helmets at your own risk. It's easy to say the guys who use one or want one are all for having them and the guys that don't want one or don't use one are against them.
Who cares, hug a friend today and tell them they're special!
Actually you're wearing a snell rated helmet because the insurance company requires the track to make you wear one when you are on the track, under their coverage. Anyway - I'm done.