since this cold weather came upon us, I have needed to use he heated screen a bit more (as you do) on my ML270CDi (had it just 2 months) When I listen to FM radio and then switch on the heated rear screen I get interfrence on the radio. Switch it off & teh radio is fine again. Same for old audio 10, Becker traffic pro & now comand so I believe its not head unit related. I had the rear & side windows security laminated & tinted , could the installer have knocked a connector perhaps? if so what & where do I check.?