Wouldn't it be worth considering that at least when driving with the top down, you could have a usable roll bar that could be attached and locked? In other words, the base of the roll bar would be firmly anchored and the roof could be closed without the top being attached. Many of us drive with the top down most of the time anyway
I don't claim to be an expert Heinz but I believe, unless there are other sections of the roll bar (not just uprights but also 'buttresses' (slanted supports)), they offer very little real protection. This is, appears to be, why many roll bars are sold as "cosmetic" rather than genuine safety devices (at least this seems to apply in the UK).
