I've seen the posts about window mechanisms for C70's they seem to be a real weak point. In the 2000 mod. convertible I just purchased I have begun to pay more attention to a "pop" noise that occurs in about the last inch of travel as you are raising the glass. Just recently ,on very hot days , the glass will hang up at this point if the door is closed and will continue to rise if you open the door. Is this a mechanical problem with the track/guide rails or more likely a motor going bad.