At this point, we have not found we need a rear shade yet. However, on our previous DRV Elite Suites, we REQUIRED something to shade the rear window! I opted not to use an awning as when the sun is low enough, it will shine inside below the awning. Instead, I contacted Magneshade (
https://magneshade.com/product/trailer-shades/).
Magneshade is well known in the Class A groups, but they also make excellent shades for fifth wheels. The shades are held in place by strong magnets placed on the perimeter of the glass. The magnets properly placed will not be seen from the inside. As the shades are placed on the outside of the window, they are extremely effective at blocking the heat of the sun light. The are easily installed and can even have a picture or pattern printed on the shade material.
In north Texas, outside temps around 103 for weeks, when I installed the Magneshade, the inside temperature of the DRV dropped some 20 degrees within an hour! Note, the rear window was facing west! Even when the thunderstorm downdrafts came through, the Magneshade stayed in place. I ended up and ordered Magneshades for every window (including the door window) on the DRV that summer!
That said, due to our locations in our New Horizons, I have not found it necessary to invest in a Magneshade yet. But IMHO, I would use a Magneshade before an awning on the back window.
Just my two cents,
Ron