chirping at 2K-3K RPM

I've got a stock '02 P5 with 25K miles that seems to chirp or rattle at around 2,000 to 3,000 RPM. It seems to eminate from the rear of the car and sounds almost like the slight metallic chirp or squeak like a whiny break pad. After looking through the other posts about noise in the back of the car I've ruled out suspension or brakes as I can replicate the noise just by revving the engine at a stoplight. It does make the noise when I go over bumps as well. I live in Vermont and drive on some rough pavement and dirt roads. My best guess is that it's something like a heatshield rattle, muffler baffle or other loose part like a body panel or swaybar. Any thoughts?

Other than that, the car is sweeet.

get someone else to rev the car while you poke around outside to isolate the source of the noise, then go from there

i got the same problem before, and it was the rear sway bar bushing....just bring it back to the dealer if it's still under warranty.