I think this puzzle remains unsolved due to a fundamental misunderstanding. Yves Sunhill should have been the driver and builder.
Introduced to buggies during a trip to the U.S., Sunhill purchased a Strakit Bugster and had it shipped back to France. He drove it in the 1975 Rallye Côte d'Ivoire/Côte d'Azur (image below), making him the first to marry French "rallyes tout terrain" with buggies. Sunhill was a designer by trade and he began designing his own buggies, which he and mechanic Jean-Paul Sevin built at Sunhill's shop in Courbevoie.
The puzzle vehicle appears to be the first of the Sunhill-built buggies, usually referred to as "Ray Ban" based on the original sponsorship livery. It was driven by Sunhill in '76 and then by Porter/Zaniroli in 1976-77 (pnegyesi Reply#13 and photo below). Sunhill continued to race and operate as a builder well into the 1980s. Sunhill buggies were driven by Patrick Gluck, Hervé Cotel, Eric Vuillemein, Martine Rénier, Bernadette Schily and others.
Here is a photo of Sunhill in the Strakit Bugster in '75 (with Ray Ban, Total and Lothar sponsorship), along with one of "Ray Ban" driven by Porter in '76:
