Itasha is the Japanese term of an otaku fad for decorating the cars and other automobiles with images of fictional characters from anime, manga, and video games. The decorations are usually done with paints and stickers. Some people also fill up their cars with figures, dakimakura, or anything else they can find. Similar motorcycles are called itansha; while bicycles are itachari.
I forgot where I got these ads from, but check out how the Japanese car culture was customizing their mini trucks back in the day. Recipe for a vintage JDM pickup = dual Weber sidedrafts, lowering kit, alloy wheels, and fender mirrors.