Suspension knocking in new 328i

The response of carmakers amazes me at times. VW's current problem with its diesels is enough to tell you that some carmakers don't care about their customers once they've bought their cars and taken them home. It seems they then don't exist. BMW's response to you smacks of this attitude; I'd call it arrogance. It's not acceptable, as you say. Take the car back to the dealer and park it in their driveway and tell them to put up with it, or justify to your satisfaction that it is something inherent in all their cars. It sounds to me like it could be a bush problem, or a shock absorber issue. Whatever the cause it should be fixed.