The funny think is because the S6 is so heavy and so much stress on the suspension components especially the control arms, this becomes almost a major service item of you want your car to handle tip top. I know the upper control Adam went bad for me at 50k miles. Funny thing though is it is usually the bushing connected to the control arm that goes bad and the actual control arm itself is in decent shape. But when you are in there it’s easier to just replace the whole thing as trying to swap a bushing in is almost impossible.
Pay to play but imo, every 50k is recommend doing this if you want the car running tip top handling wise. Unless someone can prove some of these aftermarket kits last any longer.