2008 G6 base model w/3.5 V6 4sp auto. After about 5 mins of driving the car starts to make a metallic noise somewhere in the front of the car. It has the consistency of a plastic trim panel flapping in the wind but has a metallic sound to it. At 1st I thought it was some plastic trim that was flapping around as I drove. Its frequency and volume do not change at different speeds or during cornering. It almost sounds like a coffee can full of ball bearings rotating randomly. With the driver's side window rolled down the volume increased but did not if I rolled the passenger window down. I assumed it was the driver's side front wheel bearing so I replaced it. Upon test driving it after the wheel bearing replacement, the noise returned but it is very faint now in volume. Almost difficult to hear. Any ideas?