Passat (B6) :: 2006 - Oil Level Always Low

I have an 06 2.0t m/t which I purchased cpo w/44,500 miles on it. I love the car. It runs great. However, shortly after purchase I noticed oil level was always low. I did see here on vortex that it was a common problem w/ 2.0's so I was not overly concerned. I took my car in for service at 48,954miles. Car received scheduled maintenance and I expressed my concern about burning oil. They checked for leaks and not finding any also told me that this was a fairly common problem and that it may burn a quart every 1000-2000 miles. I drove the car for about 1800 miles and checked the oil. The dipstick showed that the car was almost dry. This seemed excessive to me so I took car back to dealer. They stated that this was extreme but they didn't know where tech had filled oil to and said different techs fill to different points(doesn't give you a warm feeling inside to know each tech does what they want).

They once again checked car for leaks and once again found none. I know the car is not leaking because it sits in my garage or driveway and there are no oil marks at all. They filled oil level to just under max and documented this on service history sheet by drawing the dipstick w/ max and min markers and then noting where they filled to. They then told me to drive the car for 1,000 miles and check oil and if it lost a considerable amount to bring it back and they would perform further diagnostics. The car is now at 51,700miles and I have driven about 900 miles since they did last check and refill. I checked oil this morning and car is at top of the min. marker so it has dropped the whole space in between max and min in only 900 miles of driving. Car just switched from original factory warranty into cpo warranty. I'm calling dealer tomorrow for appointment because I want this figured out and documented properly before cpo runs out although that's about 22months/22,000 miles away. I wonder what "further diagnostics" they can perform?