"Itasha" Anime Portrayal on Cars, Where did it start and why?

The term "Itasha" 痛車 most literally translates to "painful car." It can be interpreted as "painfully embarrassing" or "painful for the wallet." It's the act of decorating the bodies of cars with fictional characters of anime, manga, or video games. Though where did it start and why? What is its current scene or standpoint in the car scene (most notably, JDM and stance life).