Until recently, real time GPS tracking required expensive hardware and monthly subscription fees. The latest real time GPS trackers use a SIM card (like a cell phone) which allow them to update you via a web browser or SMS alerts. The unit includes a pre-activated AT&T SIM card which you will need to fund. Once the AT&T SIM card is live you can place the GSM GPS Tracker in your wives a car and see exactly where the car is at any time, or open up the microphone and eavesdrop. Genius. The unit includes two batteries and costs just over $100 here.