Chrisfix has a decent video on youtube
that I was able to follow for the most part. I was dealing with a smashed/tinted window so it was a little easier to get the glass removed — I did not use a wire as ViDA suggests though that could work well. This is my own experience so do not take this info as best practice. Initially, I was quoted between $400 (well-known glass company, not a great reputation), $500 for a private glass company with a good rep. Both were replacement aftermarket (not OEM) glass and installation. I think with all materials –replacement used/OEM glass with trim, fancy new battery powered caulking gun, primer, urethane, some plastic chisels and a metal razor blade kit w/ scraper, and 2 glass suction tools (which I never used) I was at about $250.
1- remove interior trim surrounding the glass
I didn’t completely remove the trim, just bumped it loose so it was a few inches out of the way of the glass. Plastic bone tools and an occasional hex bit. The V50 is different but I believe with the C30 you would have to get the rear seat bench out, the seat ‘back’ removed, whichever side you do. Remove the plastic panel where the rear speaker is and the plastic trim above the rear wheel well. You may or may not need to get the headliner out of the way a little.
2- Remove the old glass
Used a plastic chisel, rubber mallet and some patience to remove the majority of the glass+old urethane. Remove the urethane down to 1-2mm as the new urethane will need this to adhere to. I don’t recommend using a razor blade (plastic or metal) and handle scraper on steps (2 or 3) as I didn’t find it necessary and I ended up with a few scrapes in the paint that had to be primed. If done again, I would stick to just the plastic chisels/mallet and just take your time.
3- Clean and prep the pinch weld
I used IPA and a micro fiber towel to clean the pinch weld surface. When you get ready to prime (or when using the urethane) make sure you either wear a proper mask or are outside with plenty of ventilation Prime any bare-metal nicks or scratches . You do not need a lot of primer, it is very watery so you will make a mess if not careful — if you make a mess IPA can help clean it up before it dries. Follow drying instructions for the primer. Make sure the urethane and the primer you use will work together.
4- Prep the glass
I ordered a replacement off ebay for about $80 shipped, came with the rubber trim already attached — I think if you are lucky enough to find “new” OEM glass you will need new trim as well. I’m not positive but the C30 quarter glass may have the defroster coils built-in, you will know if you have a plug to disconnect when removing the glass — of course don’t scratch the metal wires on the glass when cleaning or scraping with a razor during prep. If you order used glass it will likely have the old urethane still attached, remove it with a metal razor at a 40/45 degree angle so you dont scratch the glass — I found if you cut straight into a section of it, then scrape at an angle you can grab a piece of it and pull up on the urethane while moving the razor along. Clean the glass where the previous urethane was (removing all of it) using the razor, then use IPA to clean it. Apply primer along the entire edge of the glass where the urethane previously was. Since my glass came with the rubber trim, I did not bother removing it and didn’t find a reason to. Be sure to do a ‘test’ fit’ of the glass once everything is prepped, you can use painters tape and just line up the glass, place a couple pieces of tape at various points on the edge of the glass to the car to reference when you are at the point of installing the glass. The V50 quarter glass had an alignment peg to secure the glass on one side but the hole was bigger than the peg to it did shift a little, which the tape will help with. I would also carefully test your door to make sure it opens/closes and doesn’t shift the glass (on the v50 I ultimately fitted the glass with the door closed otherwise it would shift down, I don’t think you will have this issue with the c30).
5- prep the caulking gun/urethane
Once you have the pinch weld and glass prepped, you have to cut the tip of the urethane tube so that it produces a triangle / point when you apply it to the pinch weld. I do NOT recommend using a manual caulking gun — if you have the funds, I would absolutely get a battery powered variant as the urethane is extremely viscous. Seems ViDA also suggests this. To cut the urethane tube tip I measured 1/4″ of the tip and cut it flat then cut a triangle on one side. Do a few test runs on some cardboard applying the bead straight on, also, if using a battery powered gun make sure you have a plan on how to rotate the caulking gun to maintain the bead around the entire pinch weld before starting. If you’re just doing the quarter glass you will have a ton of urethane left over so I wouldn’t worry about running out. Apply the new urethane to the pinch weld over the existing urethane.
6- Install the glass
Install the glass, lining up the painters tape that you had before, press and hold in place. You can apply more tape at the top in case you’re worried about the glass sliding but the quarter glass doesn’t move much with the rubber trim on it. Let it cure for 24 hours (or check the instructions on the stuff you use). I think it recommended temps above 50 degrees but that may vary.
7- Test for leaks
make sure the glass is dry and the urethane cured. Hose down the outside of the quarter glass around the edges and trim to see if any water runs down the glass in the inside.
Overall it was not very difficult with the right tools and prep work. If I had full coverage insurance, didn’t have alternate transportation, didn’t have a dry / covered place to work and store the car I would probably pay someone else to do it. $500 for that tiny glass installed was enough motivation for me to try it out 