As title suggests i am getting interference on my radio when i out the heated rear screen on. The signal seems ok when in normal use but as soon as i press the button for the heated screen the radio goes all hissy and only returns to normal once i turn off the heated screen. I did do a google search for this issue but didnt see any answerss to help solve the problem. I have checked the back of the stereo and thats fine no issues there. I took the trim off the inside of the tailgate and checked the connections i spotted that one of the wires was detached from the rear window so have re-soldered this back but still got the same issue. There are 2 little FM things on either side of the screen marked left and right i done know what these are but do they boost the signal and could they be the cause of the problem?