A vehicle tracking unit is preferably for a vehicle of a type including an engine starter interrupt device. The vehicle tracking unit preferably includes a vehicle position determining device, a wireless communications device, and a controller. The controller may switch between an armed mode and a disarmed mode based upon operation of the engine starter interrupt device. The controller when in the armed mode may cooperate with the wireless communications device to send an alert message to the monitoring station and including vehicle position information, for example. The controller is also for selectively operating the engine starter interrupt device. The controller may include a combination input and output terminal for connection to the engine starter interrupt device.