I agree with all the above. Unless you have a convertable or t-tops or like to leave the windows down I would ditch the proximity sensor. Use that money for more sirens. My buddy has 4 sirens hidden throught the exterior of the car and it is pretty damn loud whne it goes off. If a thief finds one and cuts it, he still has 3 more and with the alarm blaring that loud, he is not going to stick around.