FYI, I use tracfone so I am very aware of my data usage, and my wife I function just fine with these plans. And yes, we have very nice smartphones. I have a MotoX and she has a LG G4 and we never worry about using Google Maps for directions. It uses such a tiny amount of data it really isn't an issue at all. What eats up data are photos, or more importantly, videos. Google maps uses a tiny fraction of data. I have tested it for a complete hour just to see. Anyway, I don't remember the exact amount but it was very small around 40MB for an hour if my memory is right. Anyway, just keep that in mind. We spend about $100 bucks per year on each of our cell phones, NOT A MONTH, per yearI don't have unlimited data on my cell phone so using that is not an option. I ordered the navigation upgrade flash drive for my 2013 Volt. The upgrade leaves a lot to be desired. Still many roads not listed at all that have been in existence for decades. The for price I really expected a lot more. Will have to rely on my Garmin for any serious navigation.