Yes, if it's the right film. Heat comes into a car mostly as infrared radiation, and blocking that is what actually cools a cabin, rather than simply making the window darker. Ceramic film blocks infrared, which is why a 35% ceramic tint will keep a car cooler than a much darker dyed film. It's the most common misunderstanding we deal with: people ask for the darkest tint they can get because they assume darkness equals coolness, when the technology of the film matters more than the shade.