Ooog... >_< I did not know that about them. I guess design flaw then. That would explain why the design isn't used anymore.
The seals would shrink, and once they started to shrink, it was time to get out of your car with pants wet in such a way that it looked like you pissed yourself.
Even convertibles often had that problem.
I had a 66 Mustang convertible that would leak through the seal above the windshield.
Replacement seals are often hard to find, if not outright impossible to find after only a few years.
Which forced some people to use silicon sealant to permanently seal the roof, closed.