My late friend in Muhen Switzerland, Hanspeter Humbel, was a public school shop teacher with the heart of a mad scientist with a dash of anarchist for flavor. Around 1983, he challenged himself to create a motor vehicle which would adhere to all the requirements of a passenger car on public roads.
Beginning with an engine from Renault, he created a metal frame and body then added all the required parts. When he approached the national authorities to register his creation, it seemed they were unaware of how to proceed. After he walked them through a lengthy approval process, they issued him a passenger car registration under a company name and VIN number he made up.
Don't have a photo of the car, or even remember the name, but it was definitely a rare 1 of 1 vehicle, and it's driver was far from a "regular" person.