I already have the Harman Kardon sound system in my 330XI, but I'm not sure if I want to pursue getting it in the M3. I have another 2 weeks until they will start building it. I'm just not sure if it's worth the $675 price tag, because of this annoying rattling noise and mediocre sound. I may as well get some Dyne Audio or MB Quartz speakers for around the same price. What do you all think??? [???1]