There is a problem with the stiples in the rear and most shops should tell you that, cause if they have been in business long enough they have encountered that issue before. How does all the other windows look? Some shops tint the stiples better than others. That is the defroster material that heats your glass. When installing most tint shops will turn up the defroster full blast until it heats up reall well and that helps them w/making it stick better. Or something like that I was told by the tint shop that did my windows. I'd take it back and ask what they can do to make it look better. It has to have some kind of warranty on it.