Awesome write up.....I just did this mod tonight and the shifts do feel smoother, I HAD IT OUT BEFORE AND AFTER THE MOD. For those yet to do this,,be careful of the O2 sensor...it is a liitle bulb looking thing and very delicate. I used a dremmel to clean up the sides after cutting the carbon paper out and it worked perfect....just use a shop vac to suck all the debris out as this side of the filterbox will be unfiltered when you start the car. I also wiped down the edges of the K&N I put in to suck up any excess oil. So far so good.
2009 328i Coupe Space Grey w/ Dakota LeatherSTEP, Sport Pkg. w Paddle Shifters, Prem. Pkg., Comfort Access, Grey Popler Trim, Heated Seats, Shadowline Trim, Xenon Adaptive Lights, GP Thunder Fogs, GP Thunder Angels, RE15mm Spacers, 35% Tint,OEM Alarm, Clear Corners, K&N, Strut Brace