So I replaced the rear window with a slider a few weeks back and I'm running into issues.

I replaced the butyl seal twice because I thought I did it wrong somehow the first time, but the second time I definitely made sure it was evenly placed around the window. I checked the outer plastic trim seal but it hadn't moved during both installations and wasn't leaking before. Put in a replacement seal for third brake light, and silicones the hole where the wire grommet went through.

Still getting a leak along the top of the window. Best I can guess it's the holes just outboard of the third brake light mount screws. Thinking of options to fix this so I don't have to think about it again or have a wet neck anymore. Possibly going to hit it with low expansion foam to fill the hole, then seal the outer with rtv silicone.

Or I might just break out the can of flex seal, make a human sacrifice to the patron saint of As Seen On TV (Ron Popiel) with a bit of Bolivian Marching Powder to make Ron extra happy, (he seemed to love that $H17) and then hope for the best.

Any suggestions (or willing sacrifices) would be appreciated...anyone seen Tony Little lately? He might do...

 

Did you fully inspect the plastic mount on the window before installing. The slightest crack in that piece will constantly leak regardless of what you do.
Did you check the seals around the mounting screws that hold the plastic body trim piece to the body before installing the rear window. These are a common leak point as well.

 

Checked both completely after it leaked the first time. I'm 99% sure it's coming through the holes just outboard of the brake light mounting screws. The gasket they sent with the light doesn't go around them at all.