My Red P85 was just delivered yesterday - what an absolutely amazing car!!
One of the questions I had before delivery that frustratingly literally no one could answer, despite asking numerous people in different organizations, was if navigation would work when outside of a 3G coverage area. I live in a relatively rural part of AZ and this is clearly important to me.
So, I did a couple of tests and the good news is it is functional, albeit limited. Here's the scoop on what happens when you have no 3G signal:
* You CAN do a search for an address; it will locate the address and calculate a route. However, it will only show up on the left side of the instrument screen. In the map window on the 17" display, strangely, you do get a visual representation of the route, but no map!
* Turn-by-turn visual prompts and real-time route map updates happen as normal on the left side of the instrument display and the route selection controls are active and working on the 17" display. You get the usual audio prompts.
* No satellite view or traffic of course.
I had been told that GPS was integrated into Google maps only. Incorrect - the GPS functions independently, which makes sense given that location-based HomeLink works just fine (very cool, too). Thus, I was told you could start the route within a coverage area and continue if you lost 3G, but not start one outside of coverage. This was wrong. The instrument display for turn-by-turn is provided by Navigon (eg Garmin) which it why it is still functional with no Internet connection. This is what they are talking about when they talk about the free map updates. (Not sure how that occurs yet, though.)
I have not yet tried using the address book or other advanced searches, but the good news is you'll never be lost even of you're outside a coverage area. I'll post more if I find anything else of general interest.