Your phone needs to be on.
Same technology was used to locate the lost Dragon out of Caboolture.
This technology was used in Melbourne in the Jill Maeger case where she was murdered. Her phone was left on, retrospectively tracked, noted to have travelled on Melbourne's Citylink, then the police matched the times that her phone passed under the Citylink toll points and then matched that to the rego of the alleged, then tracked his phone to find he took the same route as the deceased's phone.
Ever seen google maps traffic? It works because all Android (I believe) phones report back to Google at certain intervals. Google maps uses a number of algorithms to then determine if clusters of mobile phones on the road indicate the traffic condition. If iPhones did this too, traffic reporting would be much more accurate. You can download an app for Android that shows where you have been recently... Recording is on by default. If you intend committing a crime (or a crime in the eyes of your wife), you'd better turn off your phone and also don't take a car with a built in GPS because it's all in there too!