I had not really thought about using clear vinyl, but that sounds like an interesting idea. On my cab, there are three hinge mounts on the left (port) side about one inch long with 3/8 inch holes. I am thinking that maybe I could get 12 feet of 3/8 inch rod (46" + 26" + 46" + 26"), bend it into a rectangular frame around the doorway, and cover it with clear vinyl. Then maybe two magnets for the top and bottom right (starboard) corners and a small bungee in the middle. I think that might just work
Thanks again for the tips!