Last week, after having the car about 6 months, my key fob battery died and I could not start the car. I tried the various suggested places to put the fob that would still let it start (cup holder?, by the wiper?) but none of those worked. Fortunately, it happened at home and I just switched with my wife's key fob until I could get a new battery. But if it had happened a work or while out, it would have been a bigger problem. Fortunately, there is a simple way to avoid worrying about getting stuck. When you buy the CR2023 batteries (at Safeway, drug or camera stores), they often come two to a pack. I realized that you should just leave the second battery in the glove box. That way, if the fob battery dies in an inconvenient place, you can use the iPhone app to unlock the car, get the spare battery and replace it.