I also drive a 320i M Sport 2009 E90. What make it worse is that I have 18inch rims etc. Bought the car knowing that it is no super car. Honestly, you will waist your money modifying the car. On the bottom range you will have performance issues. A 1.6 Polo will give you a tough time. Fact is, get to know the car. You can't expect to run quarter miles with a 4 pod naturally aspirated motor having to pull 1.4 ton body. In my experience, for quicker acceleration, gear down. Ensure that the gear you select takes you into the 2000 revs mark or even better 3000 revs. Acceleration should feel quicker. Also remember that these cars have throttle memory. Don't expect sudden boosts when you were doing in town driving. Now on the flip side. I drive on freeways most of the time. With the 115kw motor, loads of cars has to move over when I come through. Acceleration on higher speeds, in 6th gear is not bad at all. As a family car, I get the best of both worlds. Safety, looks, economy and I can play around from time to time. I've owned pocket rockets before, and they were nice, but I am hooked to BMW now. It's a different experience. If all goes well I will trade in and get myself a 330d. Economical and powerful.