Mine sounds like a dump truck and still no word from the dealer or CSM. The noise is constant now at 4,700 miles. My wife can hear me turn into the neighborhood a1/2 mile away.
Did you have to do anything in the car, my 5s worked fine but no text with the 6plus, I turned on notifications and tried to re pair it to the car. Calls work fine but no text. :shrug: