I go to Audi showroom and take a look of the new S6, a lot different than the S4. S6 has digital trip meter,white line trim around every odo, more beautiful tail light,but what make me surprise is the S6 lack "rear diff lock " button ,which every Quattros have..why ??? And why does the A6 in Us use the old style tail light,in Europe and Asia A6 and S6 have new style tail light. R,Wiratorn