Hey Seaman and honeymonkey,
I recommend you guys to bring this issue to the attention of your Ford dealer as soon as possible so they can diagnose it. If you need further assistance, please contact Ford of Canada at 1-800-565-3673. They will be able to assist you further.
Thanks Deysha, yesterday I was at the dealer to install brand new front tires under warranty (the OEM ones had permanent flat spot), and I had the technician to listen that interference's noise. He gaves me an appointment July 11th as I will be in vacation at this moment.
He suspect something wrong with the sounds system's amplifier, or maybe a part of the alternator (condenser)as the noise was different accordingly with the load through the alternator. When I modify the load, let say by switching on the headlights, or the rear defrost, the noise is different....so it has somtehing to do with the alternator, when the engine is off there's no noise at all.
To be continued...