I need some help please. I have a strange knocking noise on my 2004 a3 Quattro. It comes and goes and happens and only when I go over speed bumps or the road is really bad. It sounds like something knocking in the engine compartment is knocking against the dashboard. I have had audi look at it twice now and the first time they thought it was the bushes (which were then replaced) and the second time I took it in it didn't happen for them and when I went out on a drive with the technician it wasn't doing it either. That was a couple of weeks back and now it has started again and has been consistent all week...and is slowly driving me crazy!! Can anyone shed any light on this as I am going to get it booked in and want it sorted once and for all. I am going spare!