When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I have mine up under my steering column, and it probably works by an elecromagnet of some sort, so whenever it moves it will go off, but for some reasn these (or at least mine) doesnt detect sway (shakin the car back and forth) i can shake it so hard the supsention bottoms out, but if i tap on the body panels, it goes of, its nutz.