When Car Window Tint fails, especially on the rear screen of a vehicle, it will appear bubbled or distorted. This generally happens due to film adhesive failure. It is more common that this will happen with cheaper, dyed Window Tint, but it can happen to better quality films as well. The angle that the rear screen of a vehicle sits at means that the window is exposed to more direct sunlight than the side windows, and the spectrum of lighting that hits the window will eventually break-down the components that the Window Tint is made of, in particular, the adhesive.