Oh yeah, I had that same problem with that. I went to the dealership to see if I can get the plastic trim around the glass. They said they can't do that. They told me that have to buy a whole new window! So I ended up buying a used rear window from an Avalanche. I bought for like $130 bucks. Be careful it's a common problems for escalade ext and avalanches because most all corners get cracked. I was trying to find a good used one. Lucky I found a good 1. Also what's nice is I got an avalanche rear window that came with factory tint which I liked better than non-tinted windows. If you have an aftermarket tinted rear window, you can see the brown defrost lines through the tint. I don't like the way it looks. Just an fyi. Check
www.car-part.com and good luck!