Comment by neogodless

I did. I tried a lot of things.

Ultimately the next day (this morning) I unplugged the charger, and hopped in the car and pressed Factory Reset, and it worked like a charm, and everything is fine now.

I don't know if charging was blocking pairing but I assume it was blocking the factory reset. (Just wish error messages were... more informative, you know?!)

I assume somehow data was... not in an ideal state... in the car's internal database, and the factory reset removed the bad data, allowing normal operation to assume.