Great idea! It could have the option to send its location only on request, using in daily driving cars. Or even better if you are close, it could know about it

Great idea! It could have the option to send its location only on request, using in daily driving cars. Or even better if you are close, it could know about it somehow (bluetooth?, NFC?) and stay in sleep mode. I was thinking about a similar thing, by creating an app which does the same, buy a low-end phone with GPS and hide it in my car.