Where should I place the device on the vehicle?

Whenever possible, place the device inside the vehicle. Under a seat, in the glove compartment, and the backseat pockets are all great options. If placing under a vehicle, attach it to a flat metal surface. Test the strength to make sure it is attached to steel and not a weak alloy metal. Place it at the lowest point to the ground and away from as much metal as possible. Do not place it where it is surrounded by too much metal as this can greatly affect reception and accuracy.