CarGo

Have you got an old android device? Like a phone or tablet. Just login into the same account on both device. Your old device will be the car. So you need to hide this device into the car with power plug. And the other device your current phone will notified when the car will move. It's easy to configure and use.

What you need:
Two device with internet connection.
Two device need to be connected to the same google account
One device (like an old phone) need to place into the car
The other device is your device the can be notified when a steal in action.

You can prevend the car steal. It's an easy and cheap method.