I recently fitted Eibach lowering springs so don't imagine I'll be needing the standard ones anymore. My car is a 2006 TFSI S-Line, non-Quattro so are in great condition.
I believe if fitted to a non S-Line A3 these will 'sensibly' lower your car by approx 15mm allround.
I can get the part number and pics later.
£90 ono. Collection from Mitcham, Surrey.