I have this problem with my rear glass window on an 03 Boxster S, the glass is original (says sekurit saint gobain).
Somebody suggested it's a glue joint on the canvas that let go. The local Porsche mechanic can't fix it, referred me to some upholstery outfit, maybe.
I wonder if I can glue it back myself. Any pointers, pictures or links would be useful. It is a bit of an eyesore right now.
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