The traffic LED emoticon from ThinkGeek is basically “a battery powered, wirelessly controlled message sign that can be attached to the rear window of your car via the included suction cup.” Video after the break. Click here for first picture in gallery.
A remote control unit is kept in the front of the car (fixed to front window, dash, or laid in a storage compartment) to activate the messages by pressing one of its buttons.
[via ThinkGeek]