Probably a stupid question, but I was in Best Buy today and looked at the Kenwood KVT-512. It says that it's Nav and Bluetooth ready. Does that mean that it's a nav/bluetooth option or not? What exactly is that product (the sales guy didn't seem to know what he was talking about). What would be a good, moderately priced in-dash unit that would give me Nav (preferably Garmin) and Bluetooth? (Ideally, it would retract into the dash the way the 512 does. I figure that makes it less conspicuous).