I have to admit the anti-theft is pretty cool. My wife drives a 2006 V6 vert, and once she locked the car with the top down. When she went to reach into the car for something, the alarm started wailing. So the motion sensor definitely works! I'm not convinced that many people pay close enough attention to car alarms though.
On my 2005 Mustang, we didn't get the anti-theft, but instead I have Lo-Jack with the early warning system. If the car is moved or driven without the key fob, Lo-Jack will call you on your cell, home, e-mail you, and/or fax you within 15 minutes to an hour of the occurrence. If you are in the mall all day, by the time you come out your car could have been gone for several hours. This way you can get your car back within minutes or an hour.
08 Roush 427R GT Torch Red Premium
Painted Side Mirror Covers
100% Roush synthetic oil
06 V6 Vert Premium w/Pony Package