Like a lot of people in the Bay Area, our model 3 had the small triangular windo behind the rear door broken so that theives could ascertain if something valuable was in the trunk by reaching in and lowering the back seat. I covered the hole with clear tape and went to the dealer to buy a replacement. I was fortunate they had one in stock for about $200. My next stop was to the auto parts store for some sealant. I’ve never done this repair before, but it looked straight forward enough I would give it a try.
When I started taking the window out, it was not easy. The window is attached three ways. First via three plastic prongs that go into the metal of the body. Next via sealant. Finally via a small trim tab at the top. In removing the old window, I really had to wrestle it out as the sealant adheres to the glass very well and the trim is attached to the glass. Once the trim was off, I was left with the sealant with small shards of glass all over it. All of that glass has to go, so I used a screwdriver and some pliers to pull all of them out, eventually leaving nothing but a clean surface on the sealant. I was ready to put the new window in.
I put a new bead of sealant on top of the old one, and placed the window in with the tab in the trim at the upper right as the starting point. Next I wanted to get the three prongs aligned with the holes. The prong in the upper right hand corner, an inch or so from the trim tab would not go in will the trim tab connected both pieces of the trim. It’s delicate and brittle and it snapped. However the three prongs immediately went in place and the glass adhered to the new sealant. It fit and looked perfect so I let the trim tab go.
All told, this isn’t really a difficult repair. Start to finish under two hours. You need to have some good gloves and be careful as you work on the car not to scratch it. A hand held vacuum is essential. Of course, I hope to never do this again, but at least I can tell you it’s doable.