Nice whip, man. AW M Sport FTW, and I know what I'm talking about.
We are very fortunate to have the 135i, it's a beast. 20d's are not bad, awesome MPG we get in our other car. We have not chipped/remapped the engine. BMW offers a Performance Power Kit which includes a software update as well as hardware (I think bigger fan and radiator; not sure there). Check it out, mate.
Would love to get the BMWP spoiler and diffuser one day...
BTW, it's called Edition Sport in other European markets and includes Blacklines, black mirror caps, optional 313M rims (you can get other ones, at least in Germany) and blue stitching on seats and floor mats (cloth/leather and Black Dakota only), am I right?