It doesn't at all.
I tried using Sygic and Mirrorlink. Other than the fact that the Sygic application felt so 2000 and late, my Galaxy S6 crashed twice when I tried to use it and the application required a subscription. So I quickly gave up on Mirrorlink being a viable option, at least until Google Maps is supported.
Edit: I'm excited to see this development. I don't have anything to offer for the current obstacles, but I'll keep my eyes and ears open!