Is it typical for some AM stations to have a loud whistling type noise when near overhead electrical power lines (2008 RRS HSE). Mine is so bad, I can noisten to a particular news station that comes in fine on my wifes VW.
Could be, AM is quirky. Using a laptop/desktop or any RF device near a AM radio will make it whistle too. If it happens more often than around power lines have the dealer check it because in my '08 AM reception is as good as any other vehicle I've owned.