I had the same problem in the rear with the Eibach springs, I actually took the metal sleeve off and tightened the bolt down more, this allowed the spring to compress tight. In addition I used rubberized 3M spray on the shock housing, strut housing etc, especially on the parts the spring rest, fender wells, etc, this had made the suspension super quiet and other than having a little come off onto the inner wheel in the beginning, which I cleaned off with wheel cleaner, I am very please with the lack of road noise, etc