Yes, it does automatically deactivate once the car is off. You wouldn't just activate it and leave it on because what it does is makes your car believe that it is stationary - your car wouldn't be moving on your satnav screen. It didn't cost any thing to have it fitted - it was done by my brother, and the process from start to finish was less than 2 hours. It's a true plug & play solution - no need to cut or solder any wires at all. It comes with step-by-step instructions, including how to remove your trims, satnav unit etc. I reckon a pro installer can do it in about an hour, and certainly no more than 90 minutes. To be sure of the quality of the installation, if you're going to get a pro to do it for you, I would go to a CAMS certified installer, although it is a bit of over-kill for such a simple job: http://www.cam.net.a...am-shop-finder/
Ok now I have got it. Thanks so much for all of this. Picked up my new IS350 F Sport yesterday so will look into this next week once I get it back from the window tinters etc.