I remember listening to a tech podcast years ago (I have no idea which one), where they interviewed a Googler who worked on bluetooth. The discussion was horrifying.
There was one issue they hit where they updated the stack, and some enormous percentage of all Mazda cars stopped working. The Google guys were totally stumped; the changes they made had nothing to do with that part of the stack; they had only modified the Bluetooth LE stuff.
After intense troubleshooting (they were getting thousands of complaints), they figured out that there was a bug in the head units that would crash if the Bluetooth version number exceeded some arbitrary value. So there's a patch---to this day---in the Bluetooth stack that checks to see if the pairing target is a Mazda, and if so, it spoofs the version number so that it doesn't crash.
That's just one story. Bluetooth is a complete disaster, and auto manufacturers are so technically inept it's a miracle that it ever works.
You could hope that Google rolls out some patch to fix it, but it probably depends heavily on how many users are affected and how many complaints they get. You could try going to a dealer and seeing if they have a firmware update for your head unit, but that's a heavy lift with a ten-year-old car.
Sucks.