Seriously, these cases seem like giant nothingburgers.
Did you expect that your car wouldn’t have your text message when it’s displaying it on the screen or reading it out loud?
Now, is there malicious intent? Can they be retrieved by technicians at the dealership if your phone isn’t plugged in? Is it forwarding them back to Honda Corporate or Zuck himself? If so, that’s a significant problem that would probably belong to Android Auto and Apple CarPlay…they should be storing them encrypted and only be able to decrypt them when the phone is connected. But I don’t see any mention of that in the article.