Congrats on the baby, and the car also.
I had an 05 a8 3.0tdi, by far the quietest most comfy car I have ever had the pleasure of owning. The air suspension is amazing, lights up like the bridge of the uss enterprise, and is just a very pleasant place to be. Just felt a little disconnected from the road, but its not a sports car (saying that the newer ones do get a hustle on). Very light for what they are too and I'd have one over a 7 series any day.