Oh I totally agree Flyerncle,
I was simply trying to establish whether it is a requirement of open top cars to have a roll bar, (my MX-5, as standard, doesn't and nor does the latest version!) and if a roll bar is a requirement does it have to have rear diagonal braces?
ie a bit like the windscreen - if you don't have one for the IVA then there's a whole bunch of stuff you don't need and therefore can't fail on
BV.