WARNING: This page is about a different car, the 2006 Audi A8, 2005 Audi A8, and 2004 Audi A8. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Installation Position Of Rear Double Clamp
Courtesy of VOLKSWAGEN UNITED STATES, INC.
When installing double clamp, ensure that bolt ends do not project over lower edge of double clamp.