I have airlift performance with 3P management on two of my 08 e92 335xi cars and love it. The only thing I had to do that RWD 3 series don't is to get some custom front sway bar endlinks made, as the ones that come with the kit are too short. This results in the front sway bar holding up the front of the car when aired out (about two inches), but with the longer endlinks the front can air out all the way. I drive my car as a year-round daily in Michigan and the only issue I've had is my cheap check valve freezing, which can be remedied with a better water trap setup or by just wrapping your hand around it for a few seconds on cold mornings.
