Well - this morning marks engine warning light number 3 in the two weeks since I have had my car. They cannot seem to fix the problem and the fault codes are exactly the same each time. The mechanic now admits that the last time he simply guessed at what it might be based on experience with regular A6 engines. This is not what I was looking to hear, nor what I was expecting from a dealer that asserts it is the largest Audi dealer in the world.
The car may be their's again very soon.....