I was reading about someone with the same knock on a NC the other day. It turned out to be a split bumpstop.
Just heard back from matey Chris and it's not helpful I'm afraid...his O/S/R wing was reversed into and repaired but over a series of 3 months it was back and forward to Mazda with a knock and they finally replaced the rear hub after the drop link and strut and it cured it.......but he messaged me back to say the noise was back and it was going back in again at 8000 miles :banghead:Thanks Tim
I hope he can recall
I really don't like the idea of driving very far on a disconnected and removed rear ARB
I might just get the drop links swapped for after-market ones, as they're much more substantial anyway