Every time I wash my D2, the rear windows streak this nasty black stuff really bad. It's especially bad with the alpine windows but it happens on the rear windows as well. To me it looks like there is a felt or caulk strip around the window. It's not leaking, I'm just trying to clean it up to avoid streaking when I wash it.

Does anyone have any idea what I'm talking about?

 

Mine does the same thing. My truck is white too! It's a real pain.

 

Also would like a fix, I've got a white truck too

 

same here

 

What you are seeing is a breakdown of the bonding cement. The rear and Alpine windows are secured to the body with the same cement as the windshield. I believe its a 3M product called windo-weld.
Not sure what you can do to fix it short of removing the window and re-bonding it. Mine does it too.

 

Ahh thanks, is that something an automobile glass company could do?

 

Yes, any windshield replacement service or auto glass company could do it. It might be cost prohibitive though based on the labor involved to pull the glass, clean the bonding cement and reinstall the glass.
The bonding cement is tough and it forms a such a bond that the glass becomes sort of a structural panel to the vehicle.
Personally, I'll just deal with the streaks.

 

Bead of black caulk over it to give it a fresh surface....

 

Thanks Ben, I actually just came back to this post to ask if I could cover/seal the degrading cement with caulk.