Well Ferdinand Porsche (who designed the Volkswagen Typ 1 aka the Beetle) worked for a good number of years (1923-32) as chief engineer at Daimler-Motoren-Gesellschaft and later Daimler-Benz. He much later went on to make the sports cars he is known for today, but even now the Porsche factory is located very close to the Mercedes-Benz one in Stuttgart.
At that time a lot of German manufacturers were interested in making rear-engined cars very much like how the Beetle then ended up to be. The Mercedes-Benz 130/150/170 H were designed and developed in the Ferdinand Porsche era, and between Mercedes-Benz and the Volkswagen, Porsche designed other very similar cars like the ones for Zündapp ("Porsche Typ 12") and NSU ("Porsche Typ 32").
When our good friend Adolf asked Porsche to design "the People's Car" (Volkswagen - Folk's wagon), it was no suprise he made it to be very much like his earlier work. If you want to put it not-so-kindly Ferdinand Porsche was sort of a one-hit-wonder; he kept reinventing the same concept of a car over and over again.

-Harry