Has anybody ever experienced a problem with their suspension being noisy on rough surfaces? I don't just mean tyre noise. This is rumbling, knocking, squeaking, and a general harshness to the ride. This has been going on for nearly three months and my local dealer are really dragging their heels over it. I've got a pair of rear shockers on order to see if that is the cause (when they arrive). Any information or experience anybody has will be greatly appreciated. Thanks.