it’s something I would do on both the iPhone and the car.
IPhone:
1. Settings>Bluetooth, look in My Devices, find your car, hit the circled i on the right and choose “Forget This Device”
2. Settings>General>CarPlay, look in My Cars, find your car, hit the > arrow, choose "Forget This Car"
3. As a backup, go into your car, start it, go into Settings>WiFi, look for your car. If you see it there, choose the circled i on the right and choose "Forget This Network".
Car:
Sadly I don't have a Honda, but you just need to remove the profile for your iPhone under "bluetooth" or 'media".
Once you have done all of those things, try pairing your device to your car again as well as whatever other steps you need to take for Apple Car Play.
EDIT: Also, this assumes you're accessing Apple CarPlay via wireless, not wired. In either case, you should take a look at this:
https://support.apple.com/en-us/HT205634