This very, very blue Audi RS 6 just turned up on Twitter this week. We found it posted over on the Quattroholic fan page on Twitter and people there guess that it is Lamborghini's Blu Cepheus. We've always heard Audi Exclusive doesn't like to encroach on Lambo's pallet but with IN (for Ingolstadt) tags we're suspecting this likely Audi Executive could order what he wants. Funny too that the car is driving past a B&O store.
For reference, here's a shot of Blu Cepheus we shot at the 2008 North American International Auto Show displayed as part of Lamborghini's Ad Personam display for your comparison.
See RS 6 Photo in High-Res