I just purchased a sunscreen from Prompt RV sunscreens just before our last 2 week trip. We went to the western side of the Sierra's so it was real hot. I was amazed at how much cooler the rig stayed in the direct sun light. It also happened that it was the week of the heat wave in west so temps were over 100* much of the time. I was a little skeptical about the suction cups holding the shade firm as I have a front door coach, and adhere the suction cups to the metal 3" frame around the window. It worker great and was easily applied from the ground by one person.
I can't recommend them highly enough for effectiveness and looks. One of our camp sites was a lake view of Shaver lake, so being able to see through them all during the day and enjoy the view was a real plus.
Now if I just didn't get stuck getting to the campground, but thats another story......