I have been reading of a number of faults - so far I have:
Condensation problem on the Avant (Lucky Yanks)
Tyre Pressure monitor being extra zealous
RS6+'s arriving with standard wheels instead of the Titanium look
RS6+'s arriving with black pedals instead of the silver ones on the continent
RS6+'s arriving without the silver number plaque
Following comments from Nordschleife
The tyre pressure monitor sensitivity is usually an atmospheric problem. The tyre pressure sensors are identical to the ones used in the R8s and Bentleys at Le Mans. If you get big changes in atmospheric pressure and humidity, the tyre pressures will change.
You can add - bonnet flexing at speed, faulty air conditioning (surely fixed by now), wind noise round wing mirrors, rear differential heat exchanger fins falling off (wrong glue), turbos, exhaust manifolds, headlight adjustment........