My roof panel doesn't have a fixing on the centre of the front edge, (it seems that most have). As a result it's very noisy at motorway speeds due to air blowing in the gap.

Is the fixing usually held on with a rivnut, or a jack nut, or if not, what fastening do you use?
I've not found rivnuts to be that effective in GRP - jacknuts are but I don't think there's enough space behind the moulding to accommodate one.

Any info or pics of how it's been done would be much appreciated.

Sorry for the delay in posting. Have attached photos of bracket supplied by GTM circa 2000.

That’s really helpful, thanks. I’ll have to make a copy of it.