Hi,
To achieve this on your car, simply remove the Nav-plus Unit ( ensure you know your radio code) . Once the unit is out, all the connectors are clearly labelled by stickers on the chassis of the unit.
As you look at the unit, its the bottom connector containing the power wires etc, my connector was black and its the last pin on the top row (opposite end to earth). It is labelled as GALA on the connector diagram / sticker.
You have 2 choices, simply cut it and your tv in motion will work all the time, but you will loose the GALA function, Alternativley (and best option), cut the wire and connect a simple rocker / toggle switch across the connections, mount the switch anywhere thats convienient and then when you want TV in motion, just flick the switch and vice versa.
Put the Nav unit back in , re-enter radio code and job done
