Tried that... no luck. I am done for today. Tried the impact too, no luck. No good way to wedge anything between the wheel and disk.

This could not be any worse. The nut is on far enough that there are no threads showing and the wheel is pretty much seated against the disk. Very little wiggle room. The nut is into the taper/seat of the wheel.

I can't believe this. I guess I never put a nut on that stud in the 10 years this rear has been under the car. Only ever used three as I was just rolling the car around.