Special shade for fridge vent area??

Have you checked the distance between the cooling unit and the outside wall? It should be less then an inch.
I just looked at photo online of your rig. The upper vent should have some kind of deflector to aim air out of vent. If nothing is there a void at the top of the refer can cause poor air flow, reducing refer efficiency.

I saw one made from PVC that hung over the refer outside. It had canvas to block the sun and had 6" standoffs. PVC does not need to be glued and can be disassembled for storage.

Another idea is to install a fan and thermostat to move the air through the back.

Something like Aluminet Shade Cloth they claim a 14 degrees cooler. Some sort of suction cup holder attachment when needed. As long as you don't stare at it you shouldn't go blind. ;)


Aluminet Shade Cloth

I once saw a shade on a frig vent that was on the side of a camper. The owner had attached two vertical holding strips of metal edging of some type to the camper. He then took a flat sheet of thin firm plastic that was wider than the distance between the strips, put one edge of it under each holding strip. This made an easily removable shade which bowed out from the side of the camper. It shaded the vents without harming air circulation. Sorry, no photos available.

Many years ago, on my old rig I installed some heavy aluminum foil to block the sun. It was installed inside vent area and in such a manner as to not block the air flow. If I remember correctly it was closer to the cooling coils then the access.

Using a small solar panel for fridge shade is an interesting idea.

I have thought about this for a while also but have not tried any thing yet. If I did something I was thanking about adding a shade with a solar panel on top that had two adjustable arms to keep the panel perpendicular to the suns rays. When traveling it would latch flat against the MH. My problem is I only dry camp for a week and have minimal electric req's and don't need solar yet.