As for the Panhard cars, they were the first cars in the world to be mass-produced. Indeed, it was in 1891 that thirty Panhard and Levassor automobiles left the workshops and that five of them were sold in the first year. If the range of vehicles was huge before the Second World War, the economic conditions after 1945 were much more difficult. Its high-end cars are abandoned in favor of simpler models and accessible to a wider audience. Nevertheless, the engineers were avant-garde. For example, the Dynavia was the first car to be studied in the wind tunnel to optimize aerodynamics. This is how the Dyna Z was created. Its structure as well as its bodywork were almost revolutionary. Its shape was all round, so much so that the aerodynamic coefficient fell below the threshold of 0.30, a real feat for the time. As for its engine, it was 851 cc for two cylinders and air-cooled.