Got my Z51 with A6 on Tuesday, Mar. 4th. The sales guy let me drive it to the gas station for a full tank of premium. As I pulled away from the parking spot I got the full Ackermann Effect. It was 28 degrees so that didn't help. I hope it improves when warmer weather arrives.
My car was pulled for the "audit" process after it was built and arrived at the dealer with 29 miles on it. I know that all the fluids were checked so a low level in the rear diff is not the issue.