If you feel sad about one VW guy saying your car is not a real "M" (even BMW badged it that way), then just remember, at least you are better off than the guy who needs to listen to uncountable people saying he is not a real "Tour" winner. Seven times over...
Little known facts about BMW: 1) The N54 is still in production and used in the current Z4 35i and 35is. 2) In a Z4 you can get sport+ steering combined with normal suspension etc by selecting DSC=off. (Update: DSC=off also offers sports steering in the M135i) 3) All Z4s with 19" wheels are still only offered with the worst performing OEM tires ever sold with a DCT equipped BMW (Potenza RE 050 RFT).