Probally been done before
Not that this may any use to any one.... or it might be for the people with low suspension.
But I was having a nose on ETKA as you do, and found a steel skid pan for the A3s PN 1j0 018 930
There is a guide here for a Jetta or Bora :-
http://pics2.tdiclub.com/pdf/Skid Pl...ion How-To.pdf
Might save someones sump but it is expensive...