The 2011 Audi A8 is a very uniquely built vehicle. First off, the body is aluminum Audi Space Frame (ASF). Each part of the body structure of the Audi A8 is built depending on their tasks in the vehicle. The image below shows the lateral roof frame (light blue) is made with a single extruded section; its cross-section changes flexibly from the A-pillar to the C-pillar.
There is a Power door close assist feature on the A8 that helps close the front and rear doors. Not sure about the details of this feature yet, but please keep it in mind.
In the image above, you can see some of the A-Pillar structure; the inner Front Pillar, which is a cast piece of Aluminum. The dead give away is the ribs on the front of the door opening. If the piece was stamped you would see a dart or a bead to add strength. A rib is used to strengthen a molded part.