If Garmin Express is working for you it asks where you'd like to put the update.
Due to the well documented issues with card reading in the 660 (hopefully cured now) I've never looked to see if Map Updater does, though I suspect it will in the "options" screen.
Not on the 550 it doesn't I am afraid..........but perhaps it isn't meant to be that simple with the 550.

Thanks for the response though.
