Waze does that. And both of them work the same way: by presuming you're not driving the car if you move slowly enough. If you get into a cab or bus, it'll lose the car.There's a free iPhone app that automatically locates your car - there must be something similar for Android.
https://itunes.apple.com/us/app/find-my-car-smarter/id547090457?mt=8
The MyChevrolet app will find it, though. If your OnStar account is paid up.