Itasha

Itasha (痛車), literally “painmobile”, is a Japanese term for an otaku fad of individuals decorating the bodies of their cars with fictional characters of anime, manga, or video games (especially bishōjo game or eroge). These characters are predominately “cute” female. The decorations usually involve paint schemes and stickers. Automobiles are called Itasha, while similar motorcycles and bicycles are called itansha (痛単車) and itachari (痛チャリ), respectively.

http://en.wikipedia.org/wiki/Itasha
http://tsaka.jp/itasha/index.html
http://itunes.apple.com/en/app/id391670599