I reported earlier that I had gotten the "disk error" message, and that the dealer ordered a replacement unit and disk, even though the unit worked perfectly after I put it in for troubleshooting. Well, they replaced the unit, and the new one works fine so far. It is not, however, a new unit. It obviously came out of another car, since two locations in North Carolina were already entered into the address book (I'm in PA). I have no problem with this as long as the unit was checked out thoroughly first. Thoughts?