I used u-shaped rubber channels in the top and sides, glued into my fiberglass car. I used screws for the fuzzies. I used small flathead screws, and countersunk the holes in the fiberglass frame. When I tightened the screws, they dimpled the metal strip, so they were below the raised fuzz. I think the same treatment would work for your felt to keep it from touching the window glass.

 

My POS '32 Victoria that was thrown together by "Downs Mfg." had the entire window felt/metal channel bondo'd in to the door. If you ever had to change it you would have to grind it out.

 

Mine is a metal car, but since I couldn't purchase the factory parts for my channel I had to locate some for other old USA made cars, and adapt them. I glued my felts in with 3M weatherstrip adhesive two years ago, and they're holding up great.

 

I've used adhesive backed fuzzy velcro. readily available in a variety of widths and the stick-um is very strong. any fabric shop will have rolls of the stuff.

N*T