Yes. IT DOES WORK - Just be sure you understand it
I own this product and have done my own tests. Yes, your car does get hotter if it's parked in the sun. You have a lot of window surface area, so you have a lot of solar heat. Not to mention, the frame of your car absorbs heat as does the dark dashboard. What do you expect a little solar fan to do?<br /><br />In my tests, I placed a thermometer/hygrometer in my car in a shaded area (the thermometer -- not the car) at about mid-level. I did this test over several days to compare the results and to account for cloud cover, etc. On a typical hot, southern summer day, my car was getting to over 138 degrees. I do not know how much higher than 138 it gets because my thermometer starts flashing 138 when it gets over 138 and doesn't climb any higher. (Side note: When I had this same thermometer in my car in the summer in Arizona, the outside temperature was 112 degrees. This same thermometer not only flashed at 138, but the liquid crystals in the display turned the screen completely black until the thermometer cooled down some! -- That's HOT!)<br /><br />Again, I had the same results for several summer days. I then used one of these solar fans on the side where the afternoon sun was shining. At the same time of day where my car would have been 138+ inside, I read 108. I did this for a few days to compare the results. Some days it was about 110 inside, one day 105.<br /><br />My conclusion is that the fan is working. Lowering my inside temperatures down by 30+ degrees allows the A/C to cool my car's cabin down faster.<br /><br />I have been using this product for a few years now. I use two. One on each side of the car to catch the pre-afternoon sun (eastern sun) and the afternoon sun (western sun for when I'm leaving work.)<br /><br />Something that is also effective is using a windshield sun guard. You know the one, where you unfold it and it has a shiny surface that you put behind your rear view mirror and on your dashboard.<br /><br />Ideally, it would be nice to have a thin film solar panel on the roof of my car that can power the car's internal blower without draining the battery. This would solve the problem of having to remember to put this little fan in the window along with the rubber 'weather stripping.'<br /><br />I recommend this if you can't park in the shade. Be warned too that if it stars raining heavily, even with the rubber strip in your window, you can get some water in your car.
Rating: 4 stars