I did not... every time I had someone look at it, the noise mysteriously went away. Funny that you inquiry several years later because I'm noticing the noise more frequently vs. before when it seemed like it was just in extreme cold weather.

I know this was a few years back, but did you resolve your issue?

To add to this thread with a mysterious (and now solved squeak)...
For YEARS, my '97 has made a squeaking/chirping noise that could easily be described just as the OP did. To me it sounded like a loose exhaust heat shield. The kind of noise you would expect from a thin piece of metal rubbing against another piece of metal. Whenever I had the opportunity, I would check only to find they are all securely in place...
A couple weeks ago I randomly smacked the drivers side of my front bumper, just in front of the wheel, in another effort to find the noise and to my surprise, recreated the squeak/chirp. It turns out that the front-most part of the plastic fender liner was rubbing against one of those thin pieces of sheet metal behind it (behind the bumper corner). 2 minutes and a ziptie later, no more noise.

Great focus, but you can see the ziptie.