Hello Denny2005,
Thanks for reaching out to the Apple Support Communities! We understand you are experiencing some issues with connecting your iPhone to your vehicle using CarPlay. We are happy to help provide some guidance.
It sounds like you've already done some great troubleshooting steps with an Apple Senior Advisor. We want to go over some other steps to see if we can help get it working again for you. To start, have you been able to test connecting your device with the vehicle using a wired connection for CarPlay? Are you able to connect other Bluetooth devices to your iPhone without any issues?
How to connect your iPhone, iPad, or iPod touch to your car
If you haven't already tried, try removing any paired devices in Settings > Bluetooth as well as in Settings > General > CarPlay and try repairing them with your iPhone.
Also, which iOS version are you running on the iPhone? iOS 14.6 should be the most recent version available. We would recommend checking to ensure that it is up to date:
Update your iPhone, iPad, or iPod touch
Keep us updated on how it goes.
Best Regards.