Originally Posted by techwhiz
Control arms or on an e90 the pieces that substitute for control arms could be worn.
The bushings wear and that allows the wheels to shift rearward under braking load.
e30, e36 AND e46 cars have this issues.
I'd look to worn suspension components.
Surprised no one else mentioned suspension components. It could potentially be control arm or steering bushings. When those things are worn you will get some feedback in the steering wheel.