The 2006 Audi A3 with 115k miles I have was burning a quart every 1k, but I had the dealer perform the PVC "extended warranty" (VW/Audi's way of saying it's not a recall but it should be). The warranty goes till 120k miles or 10 years, whichever is first. Now it burns about 1 quart every 4k of M1 0w40. The engine idles a lot smoother after the PCV change.
I did run M1 TDT for 5k and it burned a little less, but not significantly less. I decided to get the warranty work done to see if it would alleviate the problem and so far it has. I now run M1 0w40.
In addition to the PCV warranty, there's
1. Intake Manifold Runner Flap Motor
2. Camshaft/Cam follower
3. High Pressure Fuel Pump
I got all of these replaced for free, but it only applies to 2006-2008 2.0t