Working on repairing the inner door trim panels on my 89 XJ, two door. The panels seem to be built of of cardboard or card stock and covered with vinyl. After getting some water in there several of the plastic retainer things that hold the inner panel to the door have pulled out of that soggy cardboard backing. I'm thinking of maybe coating the cardboard with epoxy or ??? and letting it set to repair the holes in the backing and to glue the retainers back in? Anyone have other suggestions on how they've repaired those torn out retainers?

 

This sound like an excellent idea. I did this to the plastic panel on the rear hatch and worked great.

 

When I got my '87, both the wing windows had been leaking for years, causing the exact same issue. What I did was get a couple boards or that coroggated plastic (the kind you see used on political or reality signs, and used the old cardboard as a template to cut them to shape. It's been years now, but I think I picked up at Michael's or some other craft store. One other tip would be to buy replacement Christmas tree trim retainers and hot glue them into the coroggated plastic because they tend to pull out of it fairly easily.