Well, don't take a lot of stock in what you read there. Most of the time when a phone will not pair with a vehicle is because they are using older technology. As new phones are produced they represent the latest in Bluetooth technology. Automobile manufacturers do not concern themselves with updating firmware for the audio systems they install in their cars. Try this support document and see if it helps.
If you think it is the phone, what troubleshooting have you tried since you wiped the phone? Try a reset and see if that helps. Otherwise, you may need to take the device to Apple to see if something has happened to the Bluetooth chip. Can you pair the phone with any other Bluetooth device?