Crack in Fiberglass

[PaulSidiro]

Hi everyone,
I've got a 2008 294RLS which has had a crack at the rear window, top corner, the past 3 years. It's had flextape on it and no issues with leaks or anything else. Right where the blue line is in the pic.

I'm looking for feedback on what may have caused this? It happened with a previous owner, so I have no history. Perhaps a tree branch hit or hopefully not structural.
Inside the cracking, all I could see was insulation when using a scope.

I was thinking since the crack has stayed put for this long, I would repair it with new fiberglass and paint it up. Good idea?

Thanks for the feedback!
Paul

[Customer1]

Can you access it on the inside? Any exterior repair will crack again without reinforcement on the back.

[PaulSidiro]

Originally Posted by Customer1

Can you access it on the inside? Any exterior repair will crack again without reinforcement on the back.

Unfortunately I can't get to it from inside without taking down the interior panel.

I was thinking, maybe reinforcing it with a composite piece across the crack and riveting in, then fiberglass over that.

Paul