After a marten had raged in the engine room, had to be a solution. I've made my decision for the M 2500. The only drawback to the short cable, but were extended to fit and fix the unit has been installed (on the side of the battery cover / Vectra C) that may radiate it freely into the engine compartment. This is important, because ultrasonic waves are absorbed very quickly and the device is ineffective. Since the installation is no longer a marten has strayed into the engine compartment and no Kitty is more getapst via car.