Ours just had the same problem... and I doubt that will hold, we tried a high strength epoxy and it only worked one time. But who knows - maybe your solution will work, what is the stuff you're using?
I think you can order that one piece that broke but im still looking into it. For now the window just stays up but luckily its the driver side rear window.
Story is one day I was rolling it down and then suddenly it started making cracking noises and you could hear pieces falling apart on the inside and it just stopped rolling up the window- all you could hear is the motor spinning.
Suckage.