This is a copy of a thread I replied to a month ago. I had a 350z (till 4 days ago when I sold it) and yes, the cryo cooling is good for a bump in HP - especially on warmer days like we're having now mid 80's with high humidity. Cooler dryer air compresses better than warmer moist air. The systems are relatively inexpensive and easy to connect, I'm not going to be the first kid on the block to try it though. For my Z it worked well - as far as the 335i goes - this is all new to me at this point.