I have the same issue too, and it's so annoying.
That number prior to the update it did not do that it just read the name of the person and the verbal text of the message. It's SO annoying to hear all that number info lol
Try going to settings/apps/android auto/configure in android auto/unselect show first line of messages... don't know if that'll do it or not. Mine does not read the name or number and that's the only setting I can find that might do it.
I am using apple car play and my car now announced a text received and reads the message automatically. What do I do to stop it. I don’t need anyone in my car hearing my business.