This started with the .54 update. When looting, I leave the engine of my car running, thus allowing for a quick get away. I now am aware of my car's engine revving on it's own, parked out by the street, while I'm in the house looting. When it first happened, I thought OMG, the zombies are stealing my car but don't know how to take it out of park. Every car I have used is doing it. It's a bit startling when you're trying to sneak around the house and be quiet and you hear your car's engine rev out by the street. I named my last car "Christine".