Like Don, I've used the limo-tint also ... except I use the static cling window tint ... because up north, sometimes you want the solar
gain inside the rig ... so I remove it when we're headed for the mountains or doing some cold weather camping.
I know, I know, static cling (bought at Walmart) loses its cling, shows bubbles, etc etc. But hey, folks, we're talking function over form here. It works to block the hot summer sun rays!
They're all fantastic! Seriously! I wouldn't have a trailer without one! In fact, years ago, I (and others) convinced Casita
to start offering them in new rigs. The "thermostat" is really just a blind "red to blue dial" that you can adjust to make the fan turn on and off at a certain (unknown) temperature point.
That comes in handy when you leave a pet couped up for a couple of hours and are afraid of the trailer getting hot, you can set the dial in the middle, which will cause the fan to come on, if the rig heats up long after you're gone!