Low whining noise

[ratty]

I have a low whining noise from the front end of my 6 which occurs now and again.
It sounds like the brakes are touching slightly and goes away if I lightly depress the brake pedal
It happens in a straight line or when turning but only when slowing down

Does the RS6 have a fancy pre braking system like mercedes to dry the discs prior to use?

This may be the cause

Any experts out there?

[skiwi]

no it doesn't. it sounds like a slightly warped disc, or one that is glazed.