Here is what I put together from the wire diagrams I had.
You will only be concerned with the chart on the left side.
Bose Wire Diagram - S6
2013 Audi S6 quattro S tronic
Ibis White, Black interior, LED headlights w/ LED DRLs, 20" alloy wheels w/ summer tires, Carbon Atlas inlays, Audi side assist, Front filler panel
Audio System Upgrade 3.0
2nd Place - Sound Quality Pro/Am @ 2015 IASCA World Finals
2nd Place - Sound Quality Modified @ 2015 MECA World Finals
1st Place - Sound Quality Pro/Am @ 2015 Daytona Spring Break Nationals
1st Place - Sound Quality Modified @ 2016 Daytona Spring Break Nationals
Bel STiR Plus, Blinder HP-905, BlackVue dash cams (front and rear), Black Optics grill, Window trim wrapped in gloss black vinyl, Rear and side emblems/badges painted matte black, LLumar ceramic tint (15% rear, 30% sides, AirBlue front), XPel Ultimate film, Modesta BC-03 glass coating