I have the same problem in my 2010 fpv f6 fg too. but only sometimes I notice it happen when changing gears I normaly just get the engine noise. let me know if you work it out & ill do same thing too if I have. btw I went to ford and they changed my ipod cable and module, and then my whole icc and still dose it here and there. they said im first person who heard of this happen and left me with I dont know what to do. I think its doggy earth some where or connection but ill see when I end up doing my system.