Twentieth Century Motor Car Corporation

Transsexual Jerry Dean Michael, aka Geraldine Elizabeth Carmichael attempted to scam the public in 1974 with a prototype three-wheeled two-seater sports car designed and built by Dale Clifft called the Dale that had a claimed 70 MPG rating with an MSRP of $2,000.

The car was never produced. The Twentieth Century Motor Car Corporation venture turned out to be fraudulent when the California Securities Commission began an investigation.

(text below source: Wikipedia)
Rumors of fraud began to emerge and the California Securities Commission began an investigation. Although Clifft said he still believed in the project and said that he was promised $3 million in royalties once the Dale went into production, he only received $1,001, plus a $2,000 check, which bounced. Carmichael went into hiding and was featured in an episode of Unsolved Mysteries, which detailed the fraud behind the Dale as well as the fact Carmichael was wanted. She was eventually found working under an alias in a flower shop, arrested, tried and sent to prison, where she served 32 months before she was paroled.

Carmichael eventually died of cancer in 2004.