Do ya know much about this astounding humm???
as per post on anouther site

'Welll as some of you are aware i own 089 FRP(K80FRP), I have noticed over a period of time that i have had a loud howling noice from the cars wheels. It started i would give he some stick then brake for junctions etc. Then the noice would go away, noise would stop if pressed on the brake gently.
Now it does it on a very regular basis and is driving me insane, take to garage and she stops doing it
But it has got worse, however still stops when i apply gentle pressure on the brake.
I was thinking this may be the brake humm TSB, but the noice appears to be rear (but i could be weong, it wont be the first are last ) The callipers were serviced last year but have done about 15000 miles '