For those of you that have sold your GPS units, how easy is it to transfer the maps to the new owner? I've got a 76C that I'm thinking about selling or giving away and have City Select v6 & v7 that would go with the unit. The unit as well as it's maps are registered to me on Garmin's web site. What happens when I sell it? Does the new owner just install the maps, use my unlock code and everything is A-OK? Will they be able to register it on Garmin's web site no problem?