I also read the "DO NOT USE ON PLASTIC"
I think the point they are trying to make is, IF you try to remove the film later on it would be impossible. So the cure to that is do not remove it or go to Lowe's or Home Depot, purchase a new piece of plastic. I was able to pop my plastic off 1/2 the way around the edge. Super glued it back.
Oh well, the cure is worth a piece of plastic if it does not work
FRANKM, like you I spent 10 days in Tampa in the hot Florida sun in 90° + heat. I had plenty of time to think about what to do to get rid of some of the heat and improve the A/C system.
It is amazing how hot the black window frames get on the inside from the sun. I have also come up with a special cover for the windows just in case there is no shade. It is a white Vinyl on one side a a soft fuzzy bonded material on the other side. It came from JOANN's fabrics. I used
sticky Velcro hook material above the day-night blinds, sticking the Velcro to the wall. The large window on the rear is hung on six cup hooks. When parked in the shade, I do not use the material. By the way the fuzzy side faces outside but mounted on the inside of the blind not between the window and blind.