Regarding the NA engine whine, my 2011 328i had what I thought sounded like a whiney little engine. The car was very quiet and all that I heard in normal driving was the whiney engine. I drove it for about a month and then installed BMW performance exhaust and intake. I can still hear the engine whine if I drive very easy, but once the revs are over 1,500 rpm's then I don't hear any engine whine. The combo exhaust and intake is probably not necessary to get the car a little louder. The exhaust was done first on my car and was an excellent sound. For some reason, when the intake was added, the exhaust got a lot louder. It may be a little boderline loud on such a nice car, but I am okay with it for now. I had a G37 before on which the exhaust note was quite loud. My 328i is quieter than the G37 when driving slowly or normally, but it is at least as loud or louder when driving fast. Not a bad tradeoff, IMO. This is one person's way to get over the engine whine. I really did the exhaust and intake mods to get a very little bit more performance and also to drown out the whine. The exhaust mod is so easy to accomplish and can be reversed if so desired. Obviously, the intake can easily be reversed also.