I have two roll bars on mine. They are bolted to the frame and constructed with the intent that they will save my life.
Given that, I did the geometry such that should the car end up-side-down, the roll bar should keep me from being decappitated.
I recommend that if you plan to rely on the roll bar as a safety device, you take your height ( I am 6 foot 4 inches ) in the car into account when mounting the bars.
