It was the most expensive car in the world when it was launched and it became very desirable due to its road qualities, the stance, and the luxurious interior.
Some of the most known people in the world bought a 300 Roadster. People such as Shah of Iran, King Gustav of Sweden, Gary Cooper, Yul Brenner, or Maria Callas were among the customers of the 300. The car was based on the already sumptuous top-range 300 series chassis. It was named: “Car of the world elite”.

The big, curved, front fenders incorporated the rounded headlights. The tall, silver, grille stood behind the chromed front bumper. There were two open-top versions for the 300: the Cabriolet and the Roadster. The difference was that the former featured four seats and the latter featured a fully retractable soft top, behind the two seats in the front.

The leather upholstery was fitted as standard, but the stitchings and the options list was long. Its interior was designed depending on the order. In 1955, a swivel window was introduced on the 300 Sc version.

The engine was a 3.0-liter inline-six fed by three downdraught Solex carburetors and the power output was 150 hp. It was mated to a four-speed manual, with the shifter on the steering column. In 1955, the 300 Sc was improved and a direct injection unit was installed and its power grew to 175 hp. The front double-wishbone suspension and the rear swing axle ensured a comfortable ride.