The Dr. Ing hc F. Porsche AG is a manufacturer of automobiles , based in Stuttgart-Zuffenhausen and a 50.1-percent subsidiary of Porsche Automobil Holding SE . Origin of the company is a 1931 by Ferdinand Porsche in Stuttgart, founded design office. Co-owner of Porsche AG in December 2009 with 49.9 percent of the Volkswagen AG .