plastic Window Guide for back of window busted

[pa formula 78]

So my neighbor who is a mechanic was working on fixing my driver window since I don't have the time lately. He had it apart and found the issue is with the guide on the back of the window. There is a plastic clip that hold the bottom of the window to the guide I guess, and that piece has busted? I guess he talked to the dealership and they had told him this piece is discontinued. Has anyone else had this issue, and how have you fixed it.