Duport Caddy (or later called "D510").
The very first diesel french voiturette, but not the first diesel voiturette sans permis, as you needed to have a A1 licence to drive it (knowledge of code) !
So, it was kind of "125 cc", like a Lawil/Willam for our laws. Production made by Duport, St Ferreol, Faverges, from 1978 (prototype in 1977) until 1982.
Rear engine, powered by a single cylinder 510 cc air-cooled Lombardini (good vibrations !
).