It occurred to me after I drove a rented M3 about a month ago that the lane departure warning never sounds in my car even though I have it on. I don't necessarily want it on but since it is I should be getting warnings. I was on the interstate yesterday and never heard a peep from it. I'd probably want it off anyway for Brooklyn driving because that whole experience is just dodging the double-parked cars and leaving your lane. I turned off all parking sounds for that reason as when squeezing through at slow speeds it would sound constantly.