Most companies wouldn't even warranty this stuff, if you have to go behind a quiet grocery store to hear a noise like that then other brands will label you as nitpicking and deny the claim. BMW will spend thoudsands rebuilding your engine to make you happy though, even though the noise is probably
within specifications.
Here's the kind of service you'd get from a typical brand:
http://www.pistonslap.com/
Anyways your bearings didn't fail and the part isn't deffective, it's probably just a part that's within spec that's causing excessive noise.