I have read many comments that E46 owners (with sports package 17" wheels) have tracking and vibration issues with their cars.
Here is my observation, my comments are strictly based on the E36 M3 and may not be conclusive, but it may be interesting to note none the less.
1) BMW likes to run a fair amount of toe-in in the front wheels, this creates the slower steering response in dead center (kind of like increased steering wheel play while going straight), this is done because of the high speeds that occur on the autobahns...a slightly slower response to small steering input is desired.
2) I have found that the lower the amount of toe-in in the front, the bettert he car tracks and the lower amount of vibrations (wheels out of balance syndrom). Maybe the big wide tire just don't like the additional 'scrub' that toe-in creates.
3) I am not saying that toe-out is good either, I just noted that when the fron toe-in is reduced to about .02-.04 toe-in per side, the steering is more lively, the vibrations are dramatically reduced and there is less 'tramp-lining'.
Hope this info helps some