Tony Griffiths, thanks for posting a photo of the Invacar. I had never seen one but heard about them because I had a Greeves Griffon for a time. Vancevr the early small basic cars in the early 20th century were referred to as cycle cars in the UK and voiturette in France. The GN was one of the more popular one in the UK. They were fairly basic, often cycle motors, steering by bobbin and wire, chain drive. I might guess that the micro car, as others have said, is a post WW2 invention like the famous Mini. Of course, even micro cars are bigger than the Peel 50, so I don't know what category that would fit in.
Erich in Mukilteo
Erich in Mukilteo