Strange noise from'08 3i
 

I've got a 2008 3i with about 1300 miles on it. I just drove it off the lot last week.

Sometimes under moderate acceleration, I hear an intermittent rattling sound, almost like a loose pulley or something. It's not very loud. It seems to be more pronounced in cooler tempuratures. For all I know it could be normal. I'm hesitant to take it to dealer because I'm sure they'll say nothing's wrong. Anyone hear strange noises from their new cars? Thanks for any help.