See the mechanism attached to the rear end of the car in the photo? It is a “Thanks Tail“, created by media artist Kazuhiko Hachiya.
It wags and moves like the tail of a dog and can be used as a communication tool, besides signal lights and horn. The Thanks Tail lets the car say, “I’m going first,” or “Thank you,” or “Sorry.”
I also found in a serious looking mag (Autoexpress) that a leading car accessory manufacturer has launched the Thanks Tail in Japan.