I have an 8 point roll bar in my '67 Barracuda Fastback. It was a kit I bought from S&W. Once I installed it, I knew the back seat was never going to get any use, so i deleted that and put in a firewall, which i would had have to done anyway. Like someone else mentioned earlier, even cleaning the back window on the inside is a pain in the rear now, because it is not easy to get back there. I'm a large mammal @ (5ft10, and 230lbs). My car also has subframe connectors, and front bars because i removed my inner fenders. My front bars connect from the frame rail to the firewall. No flexing, car is stiff and launches well with my 550-600hp 440/727 combo. The car is heavy because i used mild steel. With my 230 lbs, it weights 3650. On the door bars, i used swing-out kits, which make it easier to get in and out. If it was a 100% race car, I would not have installed the swing outs.

With this level of roll bar, i do not worry about street driving and it being a danger to me in a wreck.