Steig ein und stirb (1973)

Germany, during the Weimar Republic. In November 1929, traveling salesman Kurt Erich Tetzner is buried at Leipzig's South Cemetery, with his widow in deep mourning. Just three days earlier, Tetzner had burned to death in his car in a mysterious accident near Regensburg. But during the autopsy, forensic pathologist Prof. Kockel begins to have doubts...