I just purchased a 2012 hyundai accent not too long ago with 20,000 miles on it but, I am able to hear a long beep noise go off somewhere around my engine every time I shut my car off. Is this normal? It's not loud at all just enough to hear it. I've also had a situation occur where I have gone to turn my rear defrosters on and while remaining stopped at a light and i heard i vibrating noise come from the rear of the cabin but then stopped once i began to drive. Could this be related?