Thanks to JonnyG for the lead to following explanation from Audi:
Audi has responded to technical problems with the brakes at the top models Audi RS3 and TT RS offers a free brake replacement on a modified brake system.
When customers complain about delayed braking in the wet, jerking, loud squeaks and high wear half years, the manufacturer has redesigned the brake system on both models. Stephan Reil, Head of Development at quattro GmbH in Neckarsulm, where RS3 and TT RS will be built, and Florian Heuberger, Head of Technology at Audi service, announced in Auto Motor und Sport that the holders of the affected vehicles can replace the brakes for free. Affected up to 5,700 models of type RS3 from model year 2011 and 6100 TT RS from model year 2010.
Exchange of parts availability from March "All customers will be helped - free," assured Quattro Manager Reil against auto motor und sport. Modified Audi has the caliper and the pads to eliminate squeaks and most frequently occurring primarily at low speed when braking. The delay in braking effect when wet Audi wants to get through a software update in the handle. "One since June 2012 and employed in the service aufspielbares ESP update increases the frequency, the brake pads are always easily applied to the wheels with the after turning on the windshield wiper in order to displace splash," said Reil, head of development at Quattro. To reduce the thermal load on the RS3-brake, an air permeable pinhole is easy on since June 2012 right in the front apron installed, which is also upgradeable.
Into series production, the changes in the coming weeks will also be accepted. However, the exchange in the workshops could "depending on the availability of parts at least until the end of March or even longer extend" estimates Heuberger. No action lies against the Audi wear. "According to our specifications, the brake pads last about 30,000 kilometers the discs reach double the mileage -. Provided proper treatment"