When walking around the park (Far Horizons Tucson Village), I noted an unusual window in a trailer door. I had to get the whole story.
The background was the same as my experience with that factory provided RV trailer door with a single window. Can't see out and when facing the sun a lot of heat enters the trailer with that one pane of glass.
There were days when I would like to have the door open to see the outside world. However, on a cool day with just a screen, it didn't often happen. My solution to my trailer was to insert plexiglass panels in the screen door. Now I could have the door open and see the outside world and the keep the heat in or the cold out. The bad part was that there now was no screen door.
A much better -- and admittedly more expensive -- was to get a door window insert. These window inserts are designed for house doors. The trailer's owner decided that he could use an insert and put a real window in his trailer door. That is what he did.
Two views: one with the blinds open and one closed. These are dual pane glass with the blinds in between. No worry about cleaning those blinds.
The window inserts are available at: ODL
The trailer shown above has a 30 inch door with a 22 inch wide insert. Considering some trailer doors are two feet wide, the narrower 8 by 64 inch window (called a side light at ODL) might be the solution.
The gentleman has already gotten several jobs in the park to cut holes in doors and install the inserts. For $50 he will install your new insert.