I have it in the X6 and although I dont park it in the garage I have programmed it to open the garage door, handy to find out if Nicki is in or not before I park up.
An annoying thing about it is that it doesnt work unless full power has been switched on in the car. You cannot just switch on the ignition and it works, it doesnt work until you turn on the engine or turn on all the electrics with a push of the start button, without starting the car.
Its handy but if you dont have it its probably cheaper and easier to fit one of those universal openers that fit in the cigarette lighter socket.