By any chance, did you leave ANYTHING plugged in overnight, like a cellphone or iPod recharger? Was your dome light switched on and left on overnight? Geeez, not very comforting that they couldn't find a problem, especially with such little mileage. Something put a drain on your battery. This may have nothing to do with it, but .. do you know that if you roll that interior light brightner wheel (that's what I call it ..
) all the way up, your dome light will stay on? I don't know if that would drain the battery overnight, but it does drain at least somewhat .. and makes the dome cover extremely hot. Let us know if it happens again!! Bummer!!!!