you just have to keep a little sticker on the car. thats if you decide to get it done by a shop. that way you could just take it back, and they fix it free. but, id say do it yourself. buy enough to practice with a few times. if youre gonna do the door windows, those are a pain in the ass. you need to get something to prop back the rubber molding (felt, whatever) but still have it be slippery enough to slide the tint down. then the tint is under that at all times, even when the window is closed all the way (still cant roll windows down for a few days) so it wont start to catch and peel back. no seems from the outside either