a fuckin pain in the ass. You have to clean the windows with spray and a razor blade then size the sheet then get the sheet up without one spec of shit getting behind it. then you have to squeegie the shit out of it to get rid of all the bubbles...then use a heat gun to slowly dry out the water in the backing material and shrink the material a bit...then when it is set you go back and find the little bubbles you got from the material shrinking...so you take a razor and cut them like a blister and try to work them down. Then about a year later they turn purple and shitty.