Eventually got the car back in to GH Ipswich for the noisy clutch bearing combined with two replacement rear wheels (under warranty) that had corrosion blisters!
I bought a pair of Falken FK452 tyres from camskills £100.90 each as the two rear wheels were being renewed, thought i would take advantage of the free fitting They run really well with no additional road noise, so I will no doubt put them on the front as well when needed.
GH had the car two days, tyres/wheels fitted and very happy. As far as the clutch goes they have said that Nissan Technical agreed that a noisy release bearing is a character trait of the 350z and there is no fault found, apparently had another 350 in at the same time which was also comparably the same... case closed!