I couldn't agree more with Easy Rider. I have a 2013 Prius, the maps for my area are obsolete, map updates are scarce plus the update cost (if there is even an update available) is more than buying a new top of the line Garmin. I just recently bought a top of the line Garmin and use it in my Prius even though it has the NAV system already in it.The NAV system in the Prii is barely adequate and the procedure and cost to update the map is absolutely ridiculous; all models.
I certainly would not pay extra for it; a Garmin is much better.
With a 3rd party unit, your passenger can change the programming and do searches while going down the road; not so with the in-dash unit. I think that applies to all makes and models.
The A/C function you describe likely is a "remote start" function and really has nothing to do with the solar option........although they might be "packaged" together.For the A/C part there is an extra button on the fob that you can press from up to about 100 feet away to start the A/C, again with adequate battery capacity, and it will run for up to 3 minutes.
The nav doesn't impress me.