I took this cameraphone photo in Herndon on Saturday -- a Honda Element with "I'M 17!!!!!" marked up all over in window paint:
Young miss (and it was a girl -- I saw the driver, but was that ever a question?), I can guess that you're excited about turning 17, and I also realize that, generally speaking, fears of stranger danger are overblown, and that anyway, there are plenty of ways that people accessorize their cars that reveal all kinds of personal attributes, but screaming out "I'm a 17-year-old girl!" on your ride just seems like a bad idea.
(Incidentally, I remembered afterwards that I had a real camera in my pocket.)