Swiss Robert Fehlmann gave Virgilio Conrero the task to create a car to participate in the XX Mille Miglia in 1953. Conrero made a tubular chassis and used a Fiat 1400 front axle, Lancia Aurelia rear axle and tuned an Alfa Romeo 1900 engine for it. By adopting four Dell' Orto carburetors and increasing the compression ratio, the power output rose to 130 HP at 6400 Rpm. Conrero went to his friend, Turinese engineer Giovanni Savonuzzi to create a body for the car. Savonuzzi modelled a bodywork in plasticine and turned to Ghia to be built. The total weight of the car was around 800 kg, the maximum speed was 225 km/h. The car, driven by the duo Fehlmann-Vuille, started the XX Mille Miglia as number 453 (for its start time of 4.53 am) was not successful and did not finish the race. Some time later , the car got fire after being involved in an accident. This car is known as the 1953 Conrero-Alfa Romeo 1900 Supersonic
After the 1953 MM Conrero-Alfa Romeo was crashed, the engine was further tuned (e.g. adding a new twin plug head, 2 45 mm Weber carburettors instead of the 4 35 mm dellorto ones,…) to an output of 158 hp and Ghia (? confirmation needed) added a new coach on the Conrero chassis. This time the design came from a guy called Koren (Anybody who knows more of this person?) Originally the Barchetta was equipped with a canopy roof. The Fehlmann-Vuille duo participated with the car in the 1954 Mille Miglia, but again they failed to finish. This is the Autopuzzle car