Stadler has been the chairman of the board and chief executive officer (CEO) of Audi AG since 1 January 2010, and as its chief financial officer (CFO) since 12 January 2007.
From 1997 he served as head of the board for the Volkswagen Group, and additionally head of group product planning from January 2002. He served as acting chairman of the board of Audi AG and its head of finance and organization until July 2007. He also serves as the chairman of Automobili Lamborghini Holding SpA and Volkswagen Group Italia SpA. He serves as vice-chairman and member of the supervisory board at German football club FC Bayern AG.
Stadler has been a member of the supervisory board at MAN SE (alternate name Man AG) since 10 May 2007 and served as a Member of supervisory board of Volkswagen Bank Gmbh, and Volkswagen Financial Services AG. He has served as a member of the economic advisory council of Bayerische Landesbank since 1 December 2005.
In terms of education, Stadler studied business management at Augsburg University of Applied Sciences, majoring in corporate planning/controllership and finance, banking and investment.
After graduating, he started his career at Philips Kommunikation Industrie AG in Nuremberg.