Denny.....I had the same issue in my Monaco Diplomat. The screen was okay, but I got baked. Since my mirrors are viewed through the windshield, I would pull the curtain part way, but it moved around too much....so I bought this ...Retractable Auto Sun Shade
It's designed to use horizontally across the windshield as seen in their photo. I mounted it vertically to the driver's window frame. It comes with two mounts that have two sided tape. Once installed, you pull it down like an accordion. Once you let go, it will pop back up to the closed position. I added Velcro to the bottom of the shade and to the lower window frame to hold it down until I released it.
I only used the shade when freeway driving. Because I view my mirrors through the windshield, I could still see beside me with the shade down. Since it popped back up into the lock position if not held down, I could simply release if from the two Velcro tabs I installed at the bottom and it would quickly raise up.
It worked GREAT to cool me and the coach from the hot sun. My new coach came with MCD shades so I gave the shade to a friend with a Diplomat. He absolutely loves using it too!
I found a photo of the shade in use.