Brakes and other issues...

[Voodoo]

One of my brake discs is making a whirring or fluttering noise without me pressing the brake pedal,could it be they are just binding slightly and need grease to help them return ? The discs are drilled and grooved so i do expect 'fizzing' when using the brakes but not when just driving.
I also get a bang from the rear of the car going over rough sections of road. I thought replacing the rear wishbone bushes would solve this but it hasn't so am unsure as to what this could be?

[Mr-2-Fingers]

I had the same problem problem with my discs, just took the wheels off and re-greased, wheels back on an problem solved.