jamesinc I have a spare bearing, I think I offhandedly bought it ages ago from @paul0075 thinking I'll need it some day. What luck!
Did this end up to be the centre bearing?
I have a similar issue with my 240 right now :-/ I haven't inspected the bearing but for some reason i think the sound is coming from the front left side of the car. When i try do a lane change at same speed the noise changes tone.
It was whining over a month ago for a couple of days but only started doing it again yesterday.