[pantdino]

I use these from Walmart. Sunlight is radiant heat, so the goal is to reflect it back out thru the glass.


This is not the exact type I got-- you need the Regular size and the one that looks like aluminum foil on one side to reflect best.


$8 at Walmart, I got several sets and double them up so the second one reflects back what the first one lets thru. I also put one in the side window


http://www.walmart.com/ip/Auto-Expre...de-Grey/879605


They have a spring steel frame so are flexible when you are placing them and curl up into a circle for storage if you want to-- I just toss them into the back seat and floor area.