I eventually sorted the droning noise from the rear of my car....turned out it WAS the right rear wheel bearing. £40 and now sounds great. Such a good mechanic so I had him do some MOT advice work and rebuilt front right suspension (wishbone, drop link rod and track rod) for £120.
BTW not been around for a bit as I have been browsing the convertible section on bimmerforum. This is quite good to tap into for 'vert specific issues but not always heavily populated.
If you don't like the way I'm driving...get off the pavement.