Beware of Car Jackers Who Leave a Piece of Paper on Your Rear Window–Fiction!
Summary of eRumor:
A warning that says that car jackers are using a new method for distracting you in order to steal your car. They leave a piece of paper stuck to your rear window. When you get into the car, start the engine, see the paper in your rearview mirror, and get out of the car to remove it, the car jacker jumps in and drives away.
It pays to be wary of any unique scheme a thief might use to take your car but there is no evidence from law enforcement agencies that this has happened at all.