Defo leaking from the valve cover/rocker cover gasket  new one costs £15 and
the problem is the gasket goes hard and a nice new supple one will sort the
problem.

This is a common as hell problem with all Audi's and is quite simple to
replace yourself, there is also a gasket on the timing chain that could
cause the leak and is a little harder to fix but try the rocker one first
and see what happens :)

Hi,
An additional problem with my A6 is a very bad oil leak which seems to
come from "top rear".  The oil drips over the exhaust and causes an
embarrassing smell.
I asked the dealer to identify the problem.  Their diagnosis was a bad
Head-gasket.  Their estimate (incl. timing belt and water pump):
$2500.  I bought the car a couple of years ago for $2300.

Does anybody care to comment.  The car runs great, is it really the
head gasket?
What about doing such repair at home.

Thanks,

Andre