Locking torsens?

[Theron J. Bliss]

As a side point, I've learned quite a bit being on this list, but my sister drove
a 1994 100 Quattro, and then ended up buying a 1993 100 fwd.  I asked her why she
didn't bother buying the quattro and she said that the dealer told her the switch
was so you can turn off the quattro.  He said it should only be used in deep snow
and below 15 mph, or it could ruin the car, and that beyond that, the quattro was
useless (her husband was also convinced of this).  Now I knew he was full of it,
just trying to sell a car that was probably sitting on his lot a while.  But I was
told later that the switch doesn't turn off the quattro, but mearly lock the
differential.  My question then is, can you use that switch on any US Audi
Quattro, to make it 2 wheel drive?  I'd love to show them that he wasn't on their
side.  After all, it had about 70k miles on it (purchased last winter), and was a
1993 100 fwd, leather, no climate control, and they paid around $17,000.  Can
anyone say highway robbery?

-Theron