I use the foil wrapped bubble wrap from Home Depot to make window shades, with Velcro to make them removable. They have cut the radiant temps at the window from 140 to the mid 89s via IR thermometer.
We set the AC units to 60...which it gets there at night, then at the hottest part of the day (like yesterday) from 2-7 pm, it was right around 100, the main living in the coach was 72, while the front bedroom and garage were 68. Got to stay in front of the heat curve, hard to play catch up if you get behind. We also use the garage for entering and exiting the coach....to help keep the main space cool. A nice floor fan can help move air around also....
Cale