I've now got the knock sorted, it was the front right calliper having excessive movement causing a dull rattle, pins greased for now, that seems to have quiated it down.
Mechanic said the pad retaining spring isn't very tight and pads could do with changing in a couple of thousand miles.
anyone know what make pads come with new springs?
europarts stock Brembo but no memotion of springs coming with them.