I keep my 2005 National Dolphin in my yard, connected to a 50A circuit, but I want to minimize the effort/wear & tear on the RV's AC in the hot Georgia summers. A couple of weeks ago I was visiting my local Lowes Blue Box and saw that they carry 25footX48inch rolls of foil-foam-foil (FFF) insulation.
I gave them ~$40 and took a roll home.
I have used this stuff in my attic and in my workshop and it REALLY cuts out the infra-red rays which do most the the heat transfer damage to things setting out in the sun (such as my home and shop and RV).
I cut out sections that fit the windows in the RV's bed room and to wrap-around the cab-end windows and the FFF REALLY works to keep the temperature down in the RV just as it did in my shop and attic.
A serendipitous by-product is that the bed room is now a nice, cooler, darker place even when sunlight is bathing the windows and trying to fry anything on the bed.