If you get in a wreck, rescue personnel can't use the jaws of life, because the power cable amperage will kill the rescuer if cut through, and the manufacturers so far refuse to install a master disconnect for emergencies.
Wrong info, Each car is slightly different, but for the most part the main power cable is a bright color to point out that it is not a "normal" cable. Also they tend to run under the car.
Having been a volunteer firefighter for the last 18 years in a dept that does a lot of car accidents I can tell you that there is no substitute for constant training and reading up on new tech like this. In that spirit I post the following link
http://www.sceneoftheaccident.com/wst_page16.html This is a list of emergency manuals available to first responders.