Thanks for the info! I actually had to delete the wifi completely that was tied to my car stereo (Kenwood brand if it matters to someone else) and it still was not working. It wasn't until I accidentally discovered the following that it worked:
1) Delete wifi attached to car stereo
2) Once car is started plug iPhone in and allow it to connect with CarPlay
3) After a few seconds, Unplug iPhone once connected and now works on Bluetooth
Some hoops to jump through each time, but at least I don't have to keep the iPhone plugged in! Hopefully this gets fixed by Apple in the future 🤷♂️