My 12v battery died and my car started to shut itself down last night while I was driving on a highway. Luckily I was able to roll into a parking lot and call Tesla HQ. They told me that somehow the 12v battery died before the main battery and they arranged a tow. The tow truck driver wasn't able to jump the battery after removing the nosecone, and he had to drag the car onto the tow truck from the rear. It was a terrible experience (especially after having my drive unit fail while driving on a major highway last month). This was actually the second 12V battery that I've had, since the first one was replaced in December 2013. Although the state of charge of the main battery was low (less than 15 rated miles), I didn't expect the 12v battery to fail first. Has this happened to anyone else?