Well, I've found two other pictures of this car on the web : it has temporary license plates from Paris area, the front is like a production R16 but the rear is inspired by the Floride / Caravelle.
I've read in an article about the R16 in an old classic car magazine that there have been several coupe and convertible prototypes made by the factory, and that one ended in private hands, so it might be this one.
