I don't have the diesel version but I had the E46, 330i one.
Had a wild vibration when I accelerated and slowed down, there was this sort off vibration and rumbling noise from under the car, felt like the floor was vibrating every time you touch the gas pedal or let go.
Long story short, I went to propshaft in Pretoria west across pilditch and they screamed at me for driving the car like that, first though wtf and then it came to light that the center bearing on the propshaft was shot. Bought the propshaft from bemow scrapyard as the bearing at the end of the shaft isn't sold separately and bmw was asking my arm for one new propshaft, like R10000 + for it. I bought the guilbo, center bearing and a 2nd hand prop shaft, they fitted it for me for like R1500 and she was as new, sold her like that. I also had a clunk noise when slowing down or letting of the gas.
Anyway, hope this helps. Bearing and guilbo was together R3000 and then the 2nd hand propshaft due to that bearing at the end of the shaft, R2000 at bemow in Pretoria west, and R1500 for the install.