most because they can vary from piece to piece and dealing with on-line purchase returns is a hassle. There's also no guarantee that the replacement piece will be free of significant issues. Other issues like bad proportions or incorrect liveries can be spotted in the photos before you make the purchase. Those annoy me less since I'm in a better position to evaluate whether those flaws are acceptable to me based on the asking price and how badly I want a model of that particular car.