A good friend who bought an A6Q (2001, I think) on my advice from a
local independent Audi repair shop/reseller has revealed to me that
the remote to this car does nothing, not even with a new battery in
it.  Here is what she has told me:

Ok...my remote does not work.  It doesn't open anything -  like the
doors or the trunk.  I figured the battery was dead so I went to buy a
new one and replaced it.  That didn't work.  So I brought it back to
Universal  when I went to have my car inspected and the oil changed
and asked them to fix the remote.  It worked for a while in the
beginning but I couldn't open the trunk.  I called them and they told
me that Marc said that I should bring back in - which I haven't done
because I've been so busy, and I'm beginning to realize, I don't trust
them.

So, what could be causing a remote control to not work correctly? Mine
all work just fine with my A4Q, so I think she has a real problem that
this shop is not fixing.  Before I go on a rampage with the shop, I'd
really appreciate some guidance as to possible causes and solutions.