Solar fan for a hot car?

Have you seen this? The Auto Cool Solar Car Fan is a nifty gadget that's supposed to keep your interior cool(er) while your car is sitting in the sun. Down here in Texas our cars can become so hot you can bake pottery in them. I've used the windshield screens over the years, and I've found that the shiny reflective insulated type work the best. They don't fold down very small, but they are worth their weight in gold if you have leather seats (ouch!). So I saw this solar car fan on TV and thought about trying it. I figure if I put it with the screen it could work pretty well. So anyone wanna buy me one so I can try it out? I'll probably have to wait until I get another $5 off Bed, Bath, and Beyond coupon and go there to pick one up. But if it will keep my Tahoe cool in the sun, it'll be worth the money.