I was amazed to discover this postcard of a Quasar, complete with a pretty accurate description of the machine in French, on the back. (The French text is also in this folder, here: http://bikeweb.com/node/1988)
I know for certain that the photo was taken at the Paul Ricard circuit, to which I had ridden the machine for the Bol d'Or 24 hour endurance race, in September 1984, (as described at some length in the January 1985 issue of Motorcycle Sport). I remember talking to the chap who took the photo, who obviously paid good attention to what I told him! The sticker in the windscreen is the famous 'bras d'honneur' symbol of the FFMC, La Federation Française de Motords en Colère (the French Federation of Angry Bikers, similar to the BMF and MAG in the UK).
At the time this photo was taken the Quasar belonged to Neil Vass, who kindly lent it to me for the occasion, before having it painted red. Neil sold it to Shawn Grinter who repainted it bright yellow and attended a lot of FF gatherings before selling it to the National Motorcycle Museum in 2014, as seen elsewhere in this gallery.
I suspect that the 'police' Quasar in the small photo above the main one is an earlier version of the 'doctor' Quasar pictured here, although I can't be sure: http://bikeweb.com/node/3041
PNB
Paul Blezard archive.