Article about S6 V10 carbon build up.
 

http://jalopnik.com/this-is-what-hap...udi-1691976274

Images:
http://imgur.com/a/0jqb5
http://imgur.com/a/wXuWi

I think Italian tune up or not, the direct injection design means no fuel passes over the rear side of the intake valves which cleans the combustion gas residue, which over time will build up on the intakes and is a trade of for the gains of the design, with periodic cleaning being an unofficial service requirement.

That's a carbon copy (no pun intended) of what mine looked like dismantled. The broken bit on mine wasn't the connecting rod, it was the shoulder on the flap nearest the oil breather inlet.

I must remember to drive it more, and harder, from now on +++