I agree. You must be crazy to leave her alone in the car. You're very lucky someone hasn't taken her yet. Please don't do that anymore. When I see dogs left in cars, if it's the least bit warm, I call the police. She's barking, because she doesn't want to be left alone in the car. She's probably scared, poor baby!
It's a big, scary world out there if you're a little yorkie! I feel sorry for your little girl that you think so little of her!