Here is the best example of how hot the interior inside side of the roof gets 139 F under the solar panels when the interior is insulated with R19 denum. This heat would normally migrate into your RV or trailer. I would guess the solar panels may even be 150+ deg F sitting in the full sun. The interior temp is a comfy 68 - degrees
In the early mornings one gets just the opposite effect. The exterior outside temp is around 57 degrees, my interior temp was 62 because I kept the doors wide open & I love cool weather down to 45 deg F is my favorite. This temp drop is due to condensation & radiation of a metal surface of its heat into space.
Now if only I could figure out how to get some tubing along the attic, collecting the extra heat in the day time for hot water storage latter in the day & during the night collecting cold water storage for some kind of cooling during the day, then one could almost have water driven solar heating and cooling.