WARNING: This page is about a different car, the 2018 Audi A6 Quattro, 2017 Audi A6 Quattro, and 2016 Audi A6 Quattro. However, it is still accessible from the selected car via links, so may be relevant.
Courtesy of AUDI OF AMERICA, LLC
The molded tabs -arrows- on the beveled surfaces of the connecting rod pairs "1 and 2", "3 and 4" and "5 and 6" must face each other.