Somehow the small white bracket that attaches to the rear seat door glass, and fits into the regulator clip, literally snapped in half. Upon further investigation, it looks like the previous owner/someone else may have tried to repair it since their appears to be cement/epoxy on it already.

I'm trying to get the glass pane out so I can replace the piece (looks to be attached just with a simple screw), but for the life of me I can't get the glass out of the track! I even went further than the workshop manual suggests as far as taking off various trim and molding pieces, but it just seems like the glass won't physically come out of the metal door frame. Is there some trick to getting these rear door windows out? Do you have to remove the fixed portion of glass first?

Any tips would be much appreciated. This is for an '08 supercharged.