Most houses on Interstate Avenue are set back from the sidewalk, but there are two houses that bump up directly on the sidewalk. They are north of the gas station at Rosa Parks. One of them has been an arty-type place (gallery?) for some time. So someone made a funny.
Cambridge Dictionary defines autocollant as: an adhesive label or sign bearing a design, political message etc., for sticking on a car’s window etc.
This references of course, certain image of treachery.