The units that Valentine puts out which are versions and updated, are they just software or hardware updates of the sensors also? When's the last time a hardware update was put in? Can you order just sensors from them? I'd like to customize myself a Valentine unit to be more discreet. I was thinking of installing ports hooked up to the sensor wires and buy extra sensors that if you plug into those ports would cut the internal sensor and read your external sensor. Then you could place one in front and back and have a hidden unit like the 9500ci.