The first car (DOHC 8cyl. in line, 1100 cc) without blower competed at the "Coupe de la Commission Sportive" 1927, more or less the French GP before being called a GP (driver: Lescot)
The second car, a single seater built for the new formula, competed in 1931 at the French GP at Reims (supercharged DOHC 8cyl. in line, 1100 cc/1300 cc) under the Name "Demo"; (driver: V. Monteiro/Deperi) and also at the GP de Comminges as "DEMO De Coucy (driver: Luis Monteiro). This car also set a speed record at Montlhéry in 1932 (driver: Lucien Clement)
In the late 1940´s early 1950 was fitted a 2 cyl. Danvignes engine (750 cc) and the car was entered to the 1000 Miglia (wrongly spelled "Cousy"). It was said that in the 1950´s also a Gordini engine was fitted (propably Simca ?) to set a long distance record at the Montlhéry race track. Simca at that time just had entered the "Ariane" at the same track successfully.
In the 1960´s this car was still in use sometimes in the south of France. At that time owned by Daniel Turcat, early Concorde-Pilot and member of the family, formerly owning the Turcat-Méry car factory.
There is a conversation by letters between Comte De Coucy and Daniel Turcat, dating from the late sixties where De Coucy claims his engines to be capable doing up to 10 000 revs per minute.
The conversation also says that one of the early drivers was a certain "Muraour", possibly not spelled correctly and in reality could have been "Murauer", which is a common name in south Germany and Austria, maybe also Switzerland.
The French author Pozzoli wrote in the early seventies in "Le Fanatique de l´Automobile" about a third pre-war car with front wheel drive and displayed in the magazine one picture.
Apart from those FWD car, both 8-cyl. cars still exist, located in the south of Germany (the Monoposto actually equipped with a Simca engine/gearbox-unit for road-use). Both original engines exist, the earlier 2-seater car is not complete but in pieces.