WARNING: This page is about a different car, the 2015 Audi RS 5, 2014 Audi RS 5, and 2013 Audi RS 5. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Connecting Rod, Installed Location
Courtesy of AUDI OF AMERICA, LLC
The molded tabs -arrows- on the beveled surfaces of connecting rod pairs "1 and 2", "3 and 4", "5 and 6" and "7 and 8" must face each other.