I looked at the picture and immediately recognized the B5 S4 and got excited. Then I thought to myself, “Well of course that’s on the list.”

You never mentioned anything about it being donuts in the snow. As I took it, you were locking the diffs on pavement because you thought it was Front/rear/all wheel drive selectors. That’s a good way to destroy your diffs.

“there was a toggle were you could switch between FWD, RWD or AWD.”

That’s definitely it. In the fourth picture in the PD’s album you can see a small nub at the curve in the fluted part. that same nub is present on the first picture above.

I remember seeing this on MotorGeek some years back. Glad to see he finished it.