Ed Newton (worked on orbitron, did shirt design for Roth, and was a grad of Art Center College of Design, Roach Studios) designed it, collaborating with Dan Woods (of Milk Truck fame), Joe Bailon (inventor of Candy Apple paint) and Bill Hines (“The Leadslinger”).
Behind the driver, and the engine, is the Pleasure Capsule, what designer Ed “Newt” Newton intended as the ultimate limousine: a lie-down compartment of shag carpeting, satin and Naugahyde with square-tufted upholstery, mirrors, about half a dozen faux-fur pillows, a rotary phone, a bar, a black-and-white TV and a vase with flowers. All in pink.
Full gallery and write up at https://www.hagerty.com/articles-videos/Articles/2016/11/10/Pink-Panthermobile
For the only good bio on Ed Newton, read "How to Draw Crazy Cars and Mad Monsters Like a Pro"