I've been thinking about doing this since my kid broke the rear window while working on the mechanism - well, not quite fair, it shattered when he closed the tailgate. Anyhow, it seems to me that lexan or plexiglass can just be installed in place of the glass. It might take some modification to the tracks, but seems workable. If all else fails, the glass is only $99.00 from LMC. CA has had a drought for a couple of years -- it's rained three times since the window broke.