mnx
2018 M3P
Tesla has made the mistake of connecting too many of the cars features to the Internet so they need to be very carefully how they handle this. There could very well be a huge pr nightmare when that functionality goes away without paying a monthly fee. And I'm sorry but "You can tether the car to your phone" is not a good answer.
I find wifi tethering to be rather crappy on my phone and phone's I've used in the past. (slow and unreliable). Perhaps that's just my carriers network, I don't know. I wonder if a USB "datastick" would work in the Model S and if you didn't want to buy access from Tesla.