Looks like the Chrysler Airflow, or the Star Project (which became the Airflow). Both were seen by MB and Dr. Porsche while in plans/prototype stage and were liberally copied by Porsche in the development of the VW Volkskar project.

Tatra did some nice designs but until Porsche got it right with the 911, most rear engined cars either were underpowered lumps or dangerous to drive (it is said that the Tatra killed more German Officers than the Czech resistance).

The development of the Airflow/Star and Chrysler's open door policy to European designers is well covered in "Chrysler-A Man and His Dream". He assumed that there was market share enough for everyone. He was more worried about GM and Ford than MB and Porsche.