If you really want to block the heat. These are great. On another thread somebody really smart said instead of insulating against the sun heat once it’s already entered your coach, block it from coming in. I bought the windshield and side window covers on Amazon for $350. Sun guard request the year, make, color and model. They make them to custom fit your windows. They come with both color matched 3m stick on snaps. Or screw in snaps. Camped in Tenn over Labor Day 2020 in 95 degree sun. No shade. With one 13,500 AC unit I was actually able to get it below 80 in the unit during hottest part of day. Never able to do that before even after all the AC mods on this forum.
https://rvtoystore.com/?
RV Windshield Covers by Sunguard Shade Products