Have a 530 d E60 model. Following parts have been chamged:
1. Steering rack seals
2. Engine mounting
3. Lower arm bushes
4. Stabilizer bar bushes
5. Brake rotors & parts frt & rear
6. Glow plugs
7. Intake manifold seals

There is a whistling noise coming in the cabin after braking l. We tried changing the rotors and pads back to stock, but the sound is still the same. Any help will be greatly appreciated. Cant seem to get to the root of this issue.