Earl Muntz was one of those incredible eccentric entrepreneurs that come along every once in a while. Earl dabbled in the automotive industry with his electronic ideas and eventually the Muntz Jet sports car.

There is an interesting page here about a film of Earl’s life and times

Earl Muntz
Earl Muntz’s Muntz Jet

Earl William “Madman” Muntz (January 3, 1914 – June 21, 1987)[1] was an American businessman and engineer who sold and promoted cars and consumer electronics in the United States from the 1930s until his death in 1987. He was a pioneer in television commercials with his oddball “Madman” persona – an alter ego who generated publicity with his unusual costumes, stunts, and outrageous claims. Muntz also pioneered car stereos[1] by creating the Muntz Stereo-Pak, better known as the 4-track cartridge, a predecessor to the 8-track cartridge developed by Lear Industries.[2]

He invented the practice that came to be known as Muntzing, which involved simplifying otherwise complicated electronic devices. Muntz produced and marketed the first black-and-white television receivers to sell for less than $100, and created one of the earliest functional widescreen projection TVs.[3] He was credited with coining the abbreviation “TV” for television,[4] although the term had earlier been in use in call letters for stations such as WCBS-TV. A high school dropout,[5] Muntz made fortunes by selling automobiles, TV receivers, and car stereos and tapes.[6] A 1968 Los Angeles Times article noted that in one year he sold $72 million worth of cars, that five years later he sold $55 million worth of TV receivers, and that in 1967 he sold $30 million worth of car stereos and tapes.[1]

After his success as a used car salesman and with Kaiser-Frazer dealerships in Los Angeles and New York City,[1][7] Muntz founded the Muntz Car Company, which made the “Muntz Jet“, a sports car with jet-like contours. The car was manufactured between 1951 and 1953, although fewer than 400 were produced.

Muntz married seven times.[8] His wives included actress Joan Barton (who appeared in Angel and the Badman with John Wayne) and Patricia Stevens of the Patricia Stevens Finishing Schools.[9] Phyllis Diller was among his many girlfriends. He was friends with celebrities such as singer Rudy Vallee, comedian Jerry Colonna, actor Bert Lahr,[6] television presenter Dick Clark, and cowboy actor Gene Autry.[8]