When is a roll hoop not a roll hoop

[BladeRunner919]

So, I was following an MX5 last night that had the roof down, when I realised that the roll hoops were lower than the driver's head. Now, I don't have roll hoops, so I kind of accept that if I flip the car I need to duck , but I wonder whether this chap realised the situation he was in? And who even designs them like that?

[Fender2004]

A lot of roll hoops are just for show and are of no use when your car over turns

[Del]

I think I read on this forum that the actual Z3 seats themselves contain "roll protection" and having felt their heavy weight, when removing them for bush and seatbelt guide maintenance, I can fully believe that.