Being a metal fabricator i took one look at the problem of the plastic tabs that hold the window in the track and came up with a permanent solution for the plastic tabs that break!
Made of metal and its all one piece so there is more contact area to glue the glass in.
http://www.vehicross.info/gallery/data/515/IMG_0028.jpg
http://www.vehicross.info/gallery/data/500/IMG_0029.jpg
www.streetboutiquecustoms.com/vx.htm