Dang, I was hoping ...
Ok, well the next step would be to see if Android Auto works with different variables. If you know someone else who has a compatible phone, try pairing their phone to your car and see if it works. Conversely, if you know someone with an Android Auto enabled vehicle that's not a Honda, then maybe you could pair your phone so see if the S7 works there.
Since Honda and Google seem to be pointing fingers, I'd not expect much help unless you want to make a big deal with both mega-corporations. I've found that in dealing with big companies, you have to scream until your blue in the face and talk to at least 5 reps until you get an answer. And no, I'm not making a joke. I've had similar dealings with Toshiba, Westinghouse, AT&T, Dell ... it's definitely not funny.
As I said, my wife's S7 Edge has some odd behavior with her car, but it's 5 years old, so I really wouldn't expect a 2016 phone to be completely compatible. That said, my Nexus 6 running stock Android 6.01 has no problems with her car, so it probably is something on Samsung's end that's just two lines of code short of a program.