It was the first coupe built by BMW after WWII and it was a disaster in financial terms.
It was built before the 507 roadster, which was another financial loss for the struggled German car-maker.

The war was over and the economy started to rise again. The American car-dealer Max Hoffman asked BMW to build a car to compete against the Mercedes-Benz 300 SL coupe and convertible. The 503 was introduced at the 1955 Geneva Motor Show and it was built as a left-hand-drive only.
With a design signed by Count Albrecht Goertz, the designer of the Datsun 240Z, the car was sold alongside the 501 and 502 sedan vehicles.

With the 503, the BMW said a firm goodbye to the pre-war forms, with tall and narrow engine compartments and curved, exposed fenders. The flush bodywork, with the doors and fenders aligned, was a modern styling. The long hood and short cabin featured four windows which could be lowered. It was more of a fake-cabriolet than just a regular coupe. The narrow and tall kidney grille was inspired by the last BMW coupe, built before WWII.

Inside, the 503 featured a luxurious interior for the era, with seating for four. It was offered with two different steering wheels, one with four spokes which looked like an X and another one with two spokes that evoked an airplane wing. The three dials on the dash were covered by a small lip on top. It was the beginning of the instrument cluster. A radio was mounted in the center.

The 3.2-liter V8 engine offered 140 hp. Unlike the 300 SL, which featured a direct injection fuel system, the BMW engineering team chose the classic carburetor system. The power went to the rear wheels via a 4-speed manual gearbox.

A vehicle that impressed the car industry back in 1956, the BMW 503 cabriolet was the first one to feature an electric soft top as standard equipment.
Its chassis was entirely made out of aluminum with its design not following any trends from abroad, entirely produced and designed at BMW.

The cabriolet was the 50s’ most expensive car, being the first one with a light alloy V8 engine that developed 150hp. The 503’s top speed was at 190 km/h. Its price equaled the price of a single family home at that time.
The elegant cabriolet was a luxury car produced in 139 units only and not many could afford it, being bought especially by wealthy people such as factory owners or film stars.
The vehicle was awarded with gold medals at car shows held in Romes, Lisbon, Wien and Cannes for its original and smooth design.

The technology used for the 503 was rather simple, the car offering great comfort for long trips. Most of the technical parts were kept from the bigger sedans, the 501 and the 502 - the frame, the engine, the transmission and the axles were almost identical.
It seemed like the new 503 represented a turning point for the BMW design, shifting to a cleaner, simpler look with the proportions of a grand turismo - long hood and short rear end.

The interior of the 503 was beautiful and clean, with 3 round gauges and a metal dashboard, plus a few ivory colored buttons that completed the luxurious design.

By the late 50’s, BMW got on the verge of bankruptcy and managed to save itself by producing small cars like the Isetta. Of course, none of them had the power of the 503, but were nevertheless more affordable.