The 501 was introduced at the 1951 Frankfurt auto show and produced 1952-1962. During the planning stage, an in-house design was prepared by Peter Schimanowski. But management was unsure of its worth, so Italian stylist Pininfarina was commissioned to create an alternative design. However, according to the link above, it was rejected because it was thought to be too similar to an Alfa Romeo design.
As we shall see below, the production 501 was conservatively styled in the general manner of some postwar English cars. It seems to have been given the ambivalent nickname Barockengel (Baroque angel) by some of the motoring public.
Less than 23,000 500-series cars were built over a ten-year span, so BMW remained financially precarious until late in that period when the Quandt family put money into the firm and the 1500 model was introduced.