i have a disco 1 '97 model. the wife rolled down a rear window and it stayed down- of course i had never been inside the door panel but as soon as i checked it out i realized it was a mechanical not an electrical problem (the motor was still engaging inside the door)... so i removed the door panel and determined that there was a broken piece- this is the roller that fits in a track at the bottom of the window- it is basically a white plastic piece. well after consulting the dealer and being told the plastic piece is only sold with an entire window regulator assembly ($100+) i decided it was time to engineer a solution. taking my broken plastic roller wheel to the neighborhood hardware store i found some brass bushings that when slid one into the other made a pretty close fascimile of the original roller. the outside diameter was perfect, the inside was a little big. I also purchased a bolt and a nylon locking nut. when i returned i removed the door regulator and motor assembly and took my handy dremel tool and removed the metal nub on the regulator arm where the plastic piece once was attached. Then I drilled the hole out where my new nut and bolt would go. After that I merely used the dremel to whittle away at the (thankfully soft) brass bushings until they were exactly the same size and thickness as the old plastic roller. after attaching it back to the regulator arm with the nut and bolt, i reassembled the power window assembly, tested it, then put everything back together. total cost of supplies: $6 total time spent: less than 2 hours including a lot of trial and error cutting and grinding the brass piece down to size! just a note to those interested in some home engineered solutions to problems!!
-robbie