Mercedes b200 -low pitch tinkling sound at front of windshield
 

Does anyone experience specific low pitch tinkling sound from outside right at front of the windshield while driving with speed of over 90 km/hr Mercedes B200?. This is not a regular sound of wind while driving a car, but really irritating unusual tinkling sound directly at front of the windshield. I carefully checked if any not securely attached parts outside of the car's body, windshield baldes and under the hood, however nothing found.