https://support.garmin.com/faqSearch/en-US/faq/content/8vzoH5r1tRANWNbfmAyxvA https://honda.garmin.com/honda/#getStartedGemini The links above will help you update your navigation map. I thought mine would be updated since i just bought the car but it was NOT. If anyone needs any help let me know I just finished mine. Its easy but takes a while. FYI you need a 16gb USB thumb drive.
I have never used the onboard navigation but I will probably update them anyway, because you never know when you might need it.
Hmm, when I go to Honda Navigation updates site for 2018, there is no listing for the Clarity. Only the Accord & Odyssey show. I'm not sure there actually is an update for the 2018 Clarity...unless I'm missing something.