Ok I was considering installing a roll bar too, I guess I need to re-think the entire concept. If you put the roll bar in and the rear seat (even though its not usable) it could get used and to me that is a safety issue. Is everyone just not using their rear seats in the cars with roll bars?
Seems like the only safe option is to design and install a bolt-in Roll Bar and cross support unit - and ONLY install it for track usage when you use a helmet.