You don't get it, do you? (And yes, I've noticed it too). The simple fact of the matter is that guessing at the immigration status based on someone's surname is not logic. It is presumption. And there's nothing wrong with it, as long as you don't pass it off as logic. With regard to the others on this thread, I refer you to my comment #36.
As I said, I don't even have to wait to hear the name. As for single-car accidents, I immediately think white, middle-class teenager.