I have my KW's set to almost as low as they will go in the rear. I dont get a bang but every once in a while you can hear metal on metal contact. It is because we dont have the oem rubber spring perch at the top of the spring anymore. The metal on the KW spring perch rubs against the metal where they meet the car and it causes some noise. If you put a flat rubber piece between the spring perch and car it will probably go away. Did for me.

rear
 

how do you adjust the rear damping or were is it at
thank u