Some of you may have been wondering what that option means when getting the VIN decoded with all the options of your car. Here are some pics of the battery main switch. It was used for delivery ex factory to mainly overseas destinations to avoid that the battery got bad/weak during shipping and storage time, it was usually removed at the local dealer at final inspection before handing over to the customer and returned to the factory for re-use.
E31 from USA
http://mydrive.roadfly.com/photos/pic.php?u=7754ApaOM&i=7406
E 36
http://xj.no-ip.org/bmw/pics/killswitch/1.JPG
http://xj.no-ip.org/bmw/pics/killswitch/2.JPG
http://xj.no-ip.org/bmw/pics/killswitch/3.JPG