The ceramic and carbon particle film absorbs heat and dissipates the heat as you are driving as the wind will cool it down.

However if you live in an area that get extremely hot and your car is parked, you will feel some heat as the constant heat from the sun beats down on the windows.

The film can only absorb a certain amount of that heat, as the film is not reflective like commercial film it can reflect only a small amount of heat.

When the film has absorbed all the heat that it can it will then allow heat to seep through.

This is very normal and when you compare the heat rejection of our film to other films like llumar, and 3M you will see that it definitely can hang with the big boys.