Originally Posted by Phil57
Well Bubbles I apologize if I was wrong. I can't find any specs on the product from the link you posted. Also I can't see how the inside screen can fit tight against the inside of the windshield. Even it it is close to the WS a gap of an inch will allow convective heat to come in the Moho and the air will circulate that heat. My understanding of the product is that it attaches with velcro and hangs down with gaps between it and the WS. If I'm wrong I apologize.
As a sunscreen professional that made his living for many years I have to say that Phil is correct.
Sunscreen on the outside will always cool better than inside.
Having it on the inside will definitely help.