No Idea what I was thinking while I installed this in my Swift .... No way will it keep the car cool but it surely will help you make it less hotter when you park it. As per various company claims they reduce your car temperature by 13 degree. Well if you park your car in the sun, interior car temperature goes up to 45 degree and with the shield it reduces to 32 degree which is in no terms cool but definitely not as hot
Spent 7K on mine to make it "not as hot". I am sure there are other benefits to it like quick cooling and all but I am not noticing as the difference might not be as much.