So folks know, I'm pretty sure now what the issue is.
This morning while cleaning up fireworks from last night I saw a rod along the rear axel clearly hanging loose on the driver's side. Closer examination indicated that it seemed to bolt up along the axle somewhere, but had come loose and was simply hanging.
Looking at my Hayes book for this car I see that this is the Lateral Control Rod, part of the suspension designed to keep tire response even. This seems to be the problem; the bolt holding it in the right place seems to have fallen out or broken.
The car has been towed back to the place I had said axle replaced back in March. They HAD to have removed this to replace the old axle, and so probably they didn't get something right or used a bad bolt or something.
I expect them to fix it under warranty.
Glad this car should be on the road soon. I want to hit 300,000 miles with it if I can.
Steve