Yep i did 350z to 335i... a simple remap sees it hit 360bhp which is looovely... i loved doing the rolling start out of an average speed zone, the way it piles on speed is just silly. Also a lot more refined inside, put still a nice tone from a straight six. Gentlemans express i called mine- in se trim it looked a lot like any other e92, but the old saying, speak softly but carry a big stick!
No probs running it, just needed half a litre of oil between services. Great car.
Looking at a 135i now as a track car, so much grunt for a very reasonable price these days.