That is the way my wife and I feel. We did not need the NAV, but it has come in handy many times.

It is kinda like Tivo. We got Tivo back in '99, and it changed the way we watch TV. A true paradigm shift. Now we can't stand to watch TV without it.

That is how nav is to us, but to a lesser degree. We love being able to type in the name of a Restaurant, and have it tell us where they are. Or when we were Christmas shopping, we needed a Toys-R-Us, so we typed it in, and went store to store till we found what we were looking for. In the past we would have gone home, gone on the internet, and printed a list of the stores. I has just made our life a little bit easier. Also, me wife could get lost trying to get out of a paper bag. Seriously, when somebody asks her for directions she actually tells them to never ask her, as she would have them in Washinton DC before they got where they were going (assuming they were going to Disney Land from Texas). Now I don't worry, as the car tells her where she needs to turn, and she can get where she is going without calling me every 5 minutes.

As far as resale goes, it might increase the price according to edmunds or KBB, but if you look at the actual selling prices of cars, and compare used cars with nav to those without, the prices are about the same. The car might sell faster, but on a money only consideration, you won't get it back. Just my humble opinion.