This car is quite widely known in France. It appears in many French Renault 4 books (l'Album Renault 4, Renault 4 de Mon Pere, etc.) and was featured in an extensive article in the French R4L magazine in June 2008 (which I saw but unfortunately didn't buy at the time).
Interestingly Jean Bertin was one of the senior engineers involved in the amazing Aerotrain 'aircraft without wings,' the early-1960s to mid-1970s 'hover' train project developed for SNCF and RATP. The Aerotrain 01 was powered by two 50hp Renault Gordini engines (hence Bertin's connections with Renault). The 'mono rail- style' tracks for the prototype Aerotrain still exist today, and can be seen running along side the main road from leading from Orlean to Paris, stopping near the main turning for Chartes. I will add some photos shortly.
In the mid/late 1970s Jean Bertin also developed a fan-powered car, which I have a small printed leaflet for somewhere. When I find it I will add some more images to the site.