Just curious on which V8 Airbox & Engine cover fits the NA. I've got the actual Airbox, which is a 1-piece unit, for the MB SLK320 on my car. And I know it is different compared to the V8 version. Purchased mine new from M-B before they discontinued the V6 version. Came from Germany for about $85 including the filter elements. Is the V8 airbox required if you perform the throttle body upgrade?