my friend has the option on his m3. it's basically a small sonar system, and beeps with greater frequency the closer you are to the object behind you.
the problem is that it becomes a continuous tone within 6" or so, and anytime you'd really use it you'd want it to go at 2" or even 1" of space. perhaps the sensitivity can be turned down, but he really doesn't even pay attention to it anymore.
i usually just turn around and look out the back glass, since that's where the car basically stops anyway. |