Through continual replacement of lower suspension arm bushes, two engine mounts and rebonding the bushes on the anti roll bar I now have solved my final source of knocking! The brackets on the end of the torque bar across the top of the engine on my S60 D5 (2001, 117k) had excess play. When the car moved from forward to reverse (or the other way) I'd get a very pronounced knock. By pushing the bar backwards then forwards would also make the clunk. I've replaced the mounts and yippee its silent! I wonder what the next noise will be. Cheers Michael.