Just bought a new sport on a 2005.
When I test drove the car, I heard the familiar high pitched humming noise from the back and thought there's a bearing needing replaced.
However, got it checked out and garage says no bearing defect, but the discs are pitted and rear tyres are cheap noisy ones - see other thread on Wanli tyres.
So, I've replaced the tyres and discs and no discernable difference noticed. The noise is still there at pretty much all speeds, i.e.from car park crawl and upwards.
Had car looked at by another garage today who thought bearings were ok and postulated that the rear offside caliper might be binding slightly.
Anyone got any other ideas?