Finaly traced the clicking at my back end to a dodgy rear CV joint (thankyou to Dreadnought) how easy/hard are they to change? I have found the part on Clever Trevor
The Cerbs aren't FWD and so going round corners shouldn't make any difference to a clicking noise as the angle of the CV joints operation will not change.
I'd expect it to rattle more on an undulating road if it were a CV joint.