Quick one, just had ap coilovers fitted to my bimmer and they look and feel great. Now the problem, they make noice when I reverse and turn. It sounds like the judder of pipes knocking together. Drives smooth and fine when driving straight forward. Any ideas what it is? Is it the coils or helper coils or are they touching something? Can't stand the sound when it happens. The mechanic assures me they are fitted correctly.