It's not a knock that sounds bad, loud or dangerous, more annoying if anything, all ball joints and bushes look OK, apart from 1 front lower (rear) control arm which I can move slightly by hand. As I have read elsewhere about the undersized pads etc which can cause a noise sounding like its coming from the suspension I just wasnt sure if it's common on q5s as its my first time owning an audi, I have worked in a garage for a year, so I will be doing the repairs myself, once I find out exactly what is causing it, I definitely arnt replacing parts unnecessarily in the hope that it solves it.