I just had it put on today and there is some king of "knocking" sound coming from the front left one, when i go over bumps. Someone told me that he had the same problem and ended up changing out the upper control arms to remedy the knocking. If that's true, so everybody that changes out their suspension on a S4 put's on new control arms? I put on the MTM/Eibach's with the stock shocks, its said to lower about 25mm-30mm. I was told that these springs are wonderful with the stock shocks. So far i'm very happy with the ride quality and height, but i have to get rid of the "knocking"

If not, probably didn't get all the bolts re-tightened with spring install.