So I was thinking I needed to replace the cardboard once again when I decided I would try to make a window track with some left over indoor/outdoor carpeting that I had laying around. It has worked so well I think I may never purchase a rear window/tailgate kit....not that I probably would anyway.
So I had already posted this in my build thread, but thought I would share here too. Hope this helps some of you guys out there in my same situation. George.