Ok so this clunk finally drove me to near insanity so I went out and took the upper control arms off (I had suspected these to be the issue), and what did I find? The HPM Megabite JR. Upper Control Arm spherical bearings had worn themselves into oblivion! Take a look, I have contacted HPM to see if I can just get the replacement bearings but I'm waiting to hear back.
In searching for the same issue I've found a LOT of people complaining about clunking in the rears of their SN95 mustangs, so check these guys. Oh and another thing, to test them you can just disconnect them from the frame and jump up and down on your trunk (with the lid open of course) and see if you get the clunk or not. That's how I concluded this to be the problem, well besides the fact the bearings are totally shot!.
In searching for the same issue I've found a LOT of people complaining about clunking in the rears of their SN95 mustangs, so check these guys. Oh and another thing, to test them you can just disconnect them from the frame and jump up and down on your trunk (with the lid open of course) and see if you get the clunk or not. That's how I concluded this to be the problem, well besides the fact the bearings are totally shot!.