I have designed a replacement light cover for Older models of Roadtrek, FMC, Airstream and many other campers and RVs/motor homes. The original manufacturer is apparently no longer selling them. I'm currently selling on Etsy under the shop name roadtrekparts you can see reviews there. 







Created with PETG (Polyethylene Terephthalate Glycol-Modified) plastic which is known for having good UV (ultraviolet) resistance so  discoloration with age won't be as much of a problem.