Last night I checked the trunk support strut...several of the bolts were not quite tight...maybe needed only half a turn to tighten them up. So that wasn't the problem.
Tonight I will try to check inside the cv joint for metal and the differential housing for any loose bolts.
Bartruff, I know it's not the top rods because they aren't in the trunk and haven't been since I bought the car.
Blas, I have checked the drive line hoop and there's no sign of any rubbing or anything hitting it. I previously tightened up the parking brake cable (it now holds) so it is not the cable hitting somewhere.
And so it goes...the mystery continues.
Bob