The UX on smartphone GPS apps is awful. My 10 year old car allows me to do things like search for gas stations and rest stops on my route and does a much better job of working with previous destinations. Cell phone GPS/Nav apps are slow and awkward to use and offer little in the way of useful features beyond simple turn-by-turn navigation.
Google Maps has supported on-the-route searching for a while - it will give you a bunch of options on the map, indicating how much of a detour each requires.
Another good one: when tapping on the Garmins, it tells you the nearest address, which can be a godsend when you are on the phone trying to meet someone. TomTom isn't as good at this, but Google and Apple maps both fail this. Try finding the nearest address to you, while driving a route, without tons of butterfingering.
The UI in my car categorizes points of interest then shows me a list sorted by range. It's a lot easier to parse while driving but the Google Maps functionality is good. Over a long distance I could see it being a bit hard to decipher. I believe my car also allows filtering by top-tier stations only.
I did not notice this functionality because I have learned to be very afraid of touching the screen while navigating with Google Maps for fear that the navigation will be cancelled and I will have to start my search over again.
