'92-'97 100 body shell rigidity

[Bewildered@aol.com]

I noticed the recent post regarding the torsional rigidity of the older 100
body shell. I'm curious as to the rigidity of the current (soon to be
replaced) A6 body which also includes the 100 since '92. How does it compare
to other cars from the same period? Is it considered a particularly rigid
design? I remember reading, back in '92, that it was 30% more rigid
torsionally than the previous model.
My second question is, did the current A6/100 descend from the previous 100
or 200 (body wise)? I've read that the S4 was the successor to the 200 TQ.
Did the '91 200 have the same body shell as the '91 100? I was never really
clear on how the lineage progressed from the '86 5000 up to today. Can any of
you fill me in?

Bill