do you notice it more at cruise or over say a bump in the road. i had a little of what you are talking about, turns out that mine was the strut tower bushing. that would be a good place to start. someone else may have a better one. just my experience good luck
Sway bar bushings also tend to squeak alot when they dry out.. Try lubing every bushing you can with white lithium grease.. If you can't get the kind in the container that you need a small brush to apply it then get ther spray type in a can