Sorry everyone, just tried this but seems not to work.
Here was my source:
Fun fact, your phone is a literal card fob if you have NFC turned on : TeslaLounge
This is an interesting one. I saw it as well but never tried it.
I've just been out to the car and spent about 12 mins down there. I was able to get it to work twice.
Made sure my bluetooth was off (the app notified me I wouldn't be able to use the phone as a key) took off my nfc ring and tried it. It unlocked.
Couldn't get it to lock and thought maybe it only unlocks so locked it. I then couldn't open.
I restarted the phone, tried again... moving the phone around etc and it unlocked again. At this point I had to come back in to work.
I'll try some more as I know it WORKS since I've done it but it's definitely hit and miss. I wouldn't rely on it at the moment.
Edit to add: I use an android phone. (Galaxy S10+) if that makes a difference.