The 17″ touch screen in Tesla’s is an amazing feature, and one of its shining use cases is maps and navigation, powered by Google*.
That asterisk is important. The images shown on the touchscreen, as well as the searching/POI database are indeed courtesy of Google. This allows always up to date street information to be viewable, as well as current points of interest to be searchable, using the onboard cellular connectivity.
The trouble is, if ever you are out of cell coverage, you would be left with no navigation. However, Tesla has that situation covered. Augmenting the Google system, is a (mostly) behind the scenes Navigon navigation system. The two work together (usually seemlessly) to route a driver to a destination, with the Navigon maps shown on the instrument cluster beside the speed readout, and Google maps on the 17″ touch screen.
This marriage of dual navigation systems does have some quirks. While navigation works while offline, you must enter a destination by street address, no POI searching is available. Also, the address better not be too recent, as the on board Navigon system may not know newer addresses . Tesla does update the onboard maps periodically over the air (for a promised 7 years free of charge), the latest update coming out about a month ago. There can be discrepancies in the data between the two. As the Navigon is used for the actual routing, it may tell you to turn at a ‘dead end’, even though Google maps (and your eyes) see a road straight ahead.