iPhone 15 Pro Max is unable to pair with my car after iOS 18.2

Try removing the iPhone from the list of paired devices in the vehicle, and then remove the vehicle from the list of paired devices on the iPhone. Restart the iPhone and car and attempt pairing again.

In addition to what ChrisJ4203 said, also try turning off bluetooth and then turning it back on. Typically that works on my Ford and iPhone, without going through Chris's steps... but occasionally I have to do both.