I parked my car, turned off the ignition switch and it started vibrating as if wasn't off. I put the key back in, started it, turned it off and it seemed fine. Got some coffee from a gas station, tried to unlock my car and it wouldn't unlock until I got right on top of it. As soon as it was unlocked my panic went off. I started the car, the alarm stopped and I drove away. Later that day, I went to start my car and it was completed dead. Something drained the battery and when we took it in, they couldn't find anything wrong with it. Also, I have a red light on my dash (not on my instrumentation panel) that stays lit after I turn off the car. Any ideas?