Originally Posted by crabman
Its a nice filter and I have no complaints about it but I could scarcely hear a difference and didn't notice the slightest difference in performance. I expected the latter, the stock box/breathing/filter is quite a robust system and there just isn't any low hanging fruit to be had there. The barely noticeable difference in sound I wasn't expecting. From reports here I was looking forward to a respectable increase in induction sound but that was not the case. It was just so as you can notice.
Have to agree with you on this. I had a BMC filter in my car and removed it only to notice little difference. I personally think that there is no performance to be had on the 2010 and up M3's by putting in a performance filter. Also a Paper filter is going to filter better than a cotton and gauze filter of the same filter area. I have posted on this topic in great detail before. To keep it short and sweet, "you can't let more air in with out letting more dirt in unless you increase filter area".
With the above being said, there is some power to be had by butting a filter in an 08/09 car that came with the charcoal element integrated with the filter. Personally, I think someone should make a solution to allow the new 2010+ filter in the 08/09 car without having to change the entire air box.