warning! blond joke ahead!
a blond has a ding in her car. she takes it into a repair shop, and he, seeing she is a dumb blond, tells her that she can fix this herself, by blowing into the car exhaust. so she goes home and does that. after an hour, her friend, also a blond, comes in, and asks, "what are you doing?". the first blond explains why she is doing that, and says "i've been going forever, but the ding wont come out!"
the second one says "dummy! you have the window's rolled down. roll them up!"