I have a UK 2019 CLA200 AMG Line. I've had it for a couple of weeks and overall I'm very pleased with it. However, at about 55mph I get a whistling sound coming from the front (though I can't tell from exactly where). It doesn't happen all the time but more often than not. At first I thought it was the wind direction but it does it on days that aren't windy! Does anyone have any idea what could be causing it?