I'm in central Texas and the temps this summer have been blistering. It's been at or near 100 degrees or more every day since early June, and, as Robert Earl Keen says, "It's been a long hot summer, not a drop of rain."
Walking in my neighborhood, I came across a car (sedan) covered with something called a Cool Cap. It covers the top of the car and all the windows.
You can find them at
http://www.itscoolinhere.com/shop/
They have five basic sizes and a tarp and claim a Cool Cap keeps the interior of a car, truck, or SUV cool as cool can be. I just went online to order one for our new van and a tarp for the pop-up and discovered that they are sold out of most car/truck sizes and the tarp, although they anticipate being restocked "in a few weeks". Was just thinking that the tarp could be configured to work as a teardrop cover without too much trouble, if you camp in a hot area without shade or if you wanted to protect a teardrop from heat & sun damage if stored outside. The FAQs state that the covers will last "a few seasons".
The material used is called Reflectionite, newly patented material. Just curious is there is any similar product that could be purchased by the yard.