I got Pete to check it, when I got the oil done about 6 weeks ago and nothing obvious was noted. Wheel bearings seemed unlikely.
We took off the wheels and put a thin film of oil between wheel and hat and checked the wheel nut torque settings. The sound seemed to dissapear for a week or so.
It's been washed once since and I knew it had come back, but on a quick fang today on some twistie roads it was very obvious.
I guess I can get the dealer to look at it when it goes in for the cable recall.