When in turn by turn navigation mode, there should be a way to easily search for a POI along/near the route, but as far as I can see when in navigation mode, the POI searching is not accessible. Ideally, this could be done with a few taps in the CarPlay UI. Maybe just a button to search, select a category and get a list showing distance to the POI and how much stopping there adds to the overall route. Mostly interesting in finding, rest stops and overnight parking.