After ordering June 29, I had not heard anything about my order except how A6's was going to preclude the production of my A4! I requested a meeting with my salesperson and saw the paperwork on my order. (Thanks to several people who emailed me with suggestions about this.) As it turned out, I have a build week of 42 (next week!) and my car is in D status.
My salesperson said he had not heard of the letter status codes. The sales manager placed a call to the Audi field rep, who was supposed to contact me yesterday...(Tim Coffman, of AoA, why haven't you emailed me like you promised!!!? )
I entered the dealership wondering if I was being dealt with honestly and left wondering why I wasn't given info that the dealership already had. The AoA rep supposedly mentioned on the phone that the side curtain airbag might be a cause for delay... has anyone heard this?
I was thinking about just cancelling the order if I didn't get some straight, honest-sounding answers.
It's hard to understand why a car company that sells to an educated, enthusiast market segment does not keep its customers informed about the process of production. It's my guess that many who have waited for their A4's would have "enjoyed" the wait more if they knew progress was being made on their order. I will update again if the AoA rep contacts me as promised.

I still think you need a different dealer. My dealer keeps me informed.

BTW, I ordered in September and also have build week #42. Ordered the sideguards too and have heard nothing about them being a cause for delay. Guess we'll know after next week.