I have already done all you have suggested in the course of checking the wheel bearings and adjusting the brakes
All the bushes are powerflex and are in place, I will have another look at the weekend though.
I have also pushed the rear end side to side very firmly in a rocking motion from both sides and nothing makes a noise, there is movement from only the tyres.
The rear axle alignment was done at HiQ, they used tracking gauges which has a laser to do the front, which is set to parallel and they have another laser which points to the rear and they were set the same on both sides.
We tried putting the gauges the other way around, as in the fronts on the rear and vice versa but when adjusting the panhard rod it made no difference because only the body is moving in relation to the rear axle.
Could the exhaust do that when cornering in both directions, I could understand when turning right, as the exhaust will move to the left, but when cornering to the left the exhaust will move to the right, away from the panhard rod
A friend has said I need to take 3 - 4 plumbline marks from the suspension down one side and then the other side, ping a line through the marks on the floor, do the same the other side and then take 2 marks from the rear axle thread bolts for the shocks and make sure the gap is the same both sides with the lines on the floor.