I see there are several bypass devices for displaying video on head units while car is not moving. For my HU, there is one wire which is to be attached to the parking brake sensor. Since the my source unit is only looking for this rather than rpms, etc. I would think I could get away with something much simpler that wiring in a bypass. My guess it that it is just looking for a voltage or close circuit. I would think I could just attach the wire to a constant voltage source equal to that of the parking brake, right? If so, where would that be?