WARNING: This page is about a different car, the 2016 Audi A3 and 2015 Audi A3. However, it is still accessible from the selected car via links, so may be relevant.
Courtesy of AUDI OF AMERICA, LLC
-- Engage the intermediate plate -1- on the sealing flange -2- -arrow B-.
-- Push the intermediate plate on the alignment bushing -A arrows-.