I have been trying to locate the source of a really annoying squeak from the front left wheel well area for about 3 months. I finally found the source and thought I would post it here in case anyone else is experiencing this noise. This noise was driving me crazy. It sounded exactly like styrofoam rubbing together. There is a splash guard in the wheel well that looks like it is meant to keep dirt and water from contacting the exhaust system. The fasteners that hold the splash guard to the frame were loose and the wind was blowing the splash guard enough to make the fasteners squeak when they rubbed against the frame. Anyway, hopefully this can help others avoid going crazy from this noise. I just used a couple of dabs of silicone to keep the fasteners from moving and the noise went away.