Most of the Audi cars have premium sound systems; Avison has made every effort to provide you with endless car infotainment while still not sacrifice your car’s original merits. If your Audi cars have BOSE system, you just have to connect the amplifier control cable in the ISO wiring harness with the amplifier control cable in the RCA cable.
Please note, it is possible that the cables shown in the photo do not fully match the supplied cables. This photo is indicative. The point is that the white and red tulip cables are connected, because the BOSE speakers in the back are controlled via the tulip plugs.