That sucks. I just bought a new to me 2016 last week and was hoping for an update in the future. The good thing is that google is releasing an update to android auto for the phones and you won't need a compatible stereo.I was told the 2016 8" nav unit is Windows CE based and might never get Android auto or Apple carplay. The 2017 Santa Fe nav unit is built on Android. They are not investing resources in Windows CE.
Just got the file from a kind forum member and it worked! Can confirm that it’s not VIN specific.
If anyone needs it just PM me, it’s only 1.5mb (the file is an installer than downloads the update directly to your memory card).
CarPlay is great!