One of our customer's Roadster had a fatal battery error (car would not turn on). I forgot the numerical value of the error code, but the nomenclature was "Sheet 9", which I assume to be the 9th sheet of 9 sheets of cells in the battery pack. Of course, the car was locked in Park, so we got a tow truck to haul it to the Tesla Service Center in San Diego. My understanding is that the battery must be dropped and sent to Fremont to have this error fixed. How common is this?