Those Pedders checks are great, the will tell you if your ball joints are stuffed. My AU suffers from a light knock from the front left when coming out of driveways and when coming to a stop when the brakes are hot. I think it's a ball joint, i've heard it's a common fault in the AU's. SikEA, surely your brakes are resonably new but if they were are replaced with the standard items it's possible that they may be warped, if you're hard on the brakes it's even more possible. The original rotors aren't very good, when I brought the AU it had a very slight shimmer at 36,000k's, i replaced them at 60,000 with DBA Slotted Rotors, because they were that badly warped that the pads were only touching about 40% of the disc face.
Cheers,
Adrian