Of course not. The car is right before us, constituted by its ever changing surface of silicone, polyfoam, and oil enamel.
Identity is performance, the art car a performer.
By the former logic, which philosophically minded cars like myself would term essentialism, the art car becomes a deviant, notable because it is not what it is supposed to be. Contrariwise, by experiential logic, the art car becomes a diva, valued because it is something special. Some people dress to express external norms, seeking to embody via their clothing the abstract essential qualities around which social consensus is constructed. These people will often say that it's what's inside that counts, many of them unaware of what is in there, or of who put it there for that matter. Other people make their bodies a site where culture is contested, literally locating themselves on their surfaces, within a much smaller field over which they can exert complete control.