I believe it's limited to 150mph. To remove the limiter would require a reflash like Evolve, Renntech or the like. Where do you want to go more than 150 mph in Canada anyway - they will take your car for that kind of speed.
Here's a video of a 335d on the autobahn after European delivery. He reaches 155mph.
http://www.youtube.com/watch?feature...&v=-AjkPQmnoWw