Hi, I own a 2000 m-roadster.It is fun.The decal on the window says 'warning equipped with anti theft radio and electronic engine lock."I am trying to figure out if the car has a broken tilt switch and broken interior movement detector or none at all. I am thinking no switch and no movement detector because when the car is locked ,I shake the car and bang on the roof ,nothing happens.A friend says I may be able to have a ' micro vision sensor ' added to my existing system for about $200 or $250 ... My goal is to leave my soft top down (for short times) and scare away any jerks who may be reaching in! comments? thanks ,from ronald