Stupid Audi. Did I mention the impossible to get to when it is in the car nut below the rewelded cat? (Thanks again Scott by the way.)
Well, with a 3/8 17mm socket, universal joint, and very long wobble extension, you can turn it 2 click at a time
right up until you run out of socket depth on a standard socket as it bottoms out on the stud and it start slipping even after you back it out so just the square past the retaining ball is working...
A normal deep socket of course won't fit.
The alternative is a box wrench with a 90 degree bend 2-3" from the head that I could make work from the top.
Worst case, I guess I will go down to HF and get a deep I can cut off. WTF cuts forged and I think hardened socket steel?
F'ing Audi...