Ok i got my coilovers installed a while back now but b4 that my ride was nice and SILENT. Once installed i noticed a knocking noise and knew it was coilover related. Just been driving day to day and trying to ignore it. Read loads of threads,people changing,engine mounts,top mounts,bushes,suspensions arms all to no avail. But i did see that someone mentioned drive shafts. I went and checked for play and i reckon thats the cause. There was around 2mm each of play in both drive shafts and the noise it made of tapping was very familiar to whats occuring while driving. So if you have coilovers check or confirm that theres play in there (left to right) I dont know if its the norm to have play in the drive shafts, (2mm) id b glad to find out its not the norm and ive found the dreaded knocking noise!