Originally Posted by roundel335
I've got a Garmin 2955 to handle navigation, which isn't dependent on being "in range" of a cell tower. It does all the things you mention plus I can just talk to it instead of playing with a touch-screen or iDrive controller.
The problem with the onboard NAV system is that it's too expensive to start with and the updates are costly and infrequent. If they'd cut the price in half and provide at least quarterly updates to the maps plus traffic alerts at no extra cost, now THAT would be something I'd buy.
iDrive Nav doesn't use cell towers; it uses GPS -- and features a better antenna (the shark fin on the roof) than is available in handheld GPSs.
That's one reason recomputing routes is so fast in iDrive Nav. With the HUD, if I vary off the route, route recalculation is almost instantaneous.