http://rvprotectionproducts.com/index.php?p=product&id=391&parent=44

I was going to install this in the rear, but now with two thule spirits side by side on the roof (have two bars, but the thules are rolling inward a wee bit, so will probably go to four bars), there isn't enough sunlight hitting the rear roof, so now I'm going to have to put this above the driver area, in the center of the first section of ac duct, tunneling straight through it, and perhaps have a t-section to the tunnel / tube, and connected to this t, a long accordian tunnel (like for dryers....) that connects to ducts in the rear, [which could be the same as those round black vent fittings that are the center front of the ac duct of a carat], and these rear ducts cold either be in the center of the last section of ac duct, or in the rearmost housing for the ac [not sure if there is room there . . . )] - - this will allow me to not seal my fate when I move to solid glass for the middle side glass . . .