Is it very cold where you are? Anyway, yesterday when it got very cold here I heard a bip-bip-bip-bip plasticky noise coming from the front -- like a piece of a belt was hitting inside the front plastic belt covers. This was after driving 120 miles. So I took it to my local honest mechanic who made the noise disappear just by applying light pressure on that cover. No more noise. He says no worries...

I wonder if a clip or screw gets loose or its looseness is exaggerated by the cold and thise allows some play in the cover. Anyway, if this is your issue, I hope thise helps...

Others porbably know much more, so we'll see who else replies.