WARNING: This page is about a different car, the 2009 Audi TT and 2008 Audi TT. However, it is still accessible from the selected car via links, so may be relevant.
-- Check the metal ring inside the pressure plate for damage -arrow-.
Fig 1: Identifying Wire Ring In Thrust Plate
Courtesy of AUDI OF AMERICA, LLC
Replace any pressure plates that have a broken metal ring.