Squeaking from rear driver's side area
 

My 2002 Z28 M6 has a slight squeaking noise towards the driver's side rear that happens when going over bumps, irregularities in the road, etc. It has progressively gotten worse over a few days. The squeaking has gotten more noticeable and now it kind of makes a low, muffled "ert" sound when going over bumps. I sprayed WD-40 in the holes of my sway bar end link bushings and even my exhaust hangars but the squeak was still there.

I haven't had enough time to get it checked out, but I have a feeling its a worn out shock? I'm actually a DIY guy but since I got my tools stolen I can't find out whats wrong myself.

Thanks!

Upper shock mount bushings. I've got the same thing on the passenger side. This winter it WILL be fixed.