I just redid my windows. I'm glad I did the plastic tabs were still in tact but had some small cracks. I simply fabricated some small metal plates that I bonded to the plastic tabs and all is good now. But, the real problem I was having was with the rubber track in the front. It's real easy for the rubber to not completely seat correctly in the forward track. There's a lip on both the inside and outside of the rubber that needs to clip over the inside and outside edge of the track. If you don't get this right the window will bind in the track. It's very easy to pull the lip off the front of the track when you install the window. This jams it into the track and the window will bind because there's too much rubber in the track. I also trimmed down the inside lip of the rubber as well. Also, it's really easy for the rubber to get pinched where it goes from the inside of the door to the outside again at the front (by the mirror). There are several different pieces of rubber that all merge at the very front of the door. If they aren't all lined up they will pinch the window as it tries to rise at the front. The window then begins to tilt forward and bind. If it's bad enough the window angle never recovers.