you need a good smart phone ideally to do it, so you can see the position on a map. Its not as good as live updating that many of the proper tracker services do, so it can be hard to follow a car thats all over the shop and being driven to evade you as you usually cant update fast enough. Good if they are unalerted to being followed as you can usually update quick enough to follow thier general direction along main roads and be close behind when they pull up.