I was told when I bought the car that the alarm was standard equipment only to find out the SA Lied of course. Then I was told by the same SA that it was not a problem because they could install it aftermarket when it arrived - lied to again. My car was not even pre-wired for it

unless it was ordered from the factory. I was also told that the vert did in fact have the motion sensor but that it was placed in a different location because it was a vert. I have no idea if that was a lie too or not because I could not have it installed on the car to find out.
I am pretty sure that BMW got enough complaints about this stupid mistake that that is why they made it standard on the 2010. From all of the discussiuons that I had with BMW NA it seemed that they had realized what a HUGE mistake they made in having it as an option on a luxury car when the cheapest of cars made have it as a standard feature. No car that I have ever owned has not had an alarm until this one. And this is the most expensive car I have ever bought.
Short answer is it depends on what your build date is as to whether or not your car is pre-wired for it. If mine was I would get it done in a heart beat - but I am kind of freaky about alarms. I love them they make me feel better whether or not they actually do any good. I know I have BMW Assist to track the car and I have LoJack on top of that and if I could have the alarm I would have it too. I am VERY mad at my sales guy for misleading me on this decision. But I am very happy with the car other than that.
As you can tell this was a HOT BUTTON for me. Sorry for the rant but I hope the info helps you some.