Popping Sound

[IronHorse]

2002 Firebird TA WS6, 22,000 Miles. I get this popping sound on the right rear when ever that wheel passes over a pot hole or speed bump... I've replaced the shocks, checked all bolts for proper tightness, I've checked all bushings, mounts, and bump stops (Panhard, LCA, Torque arm, and lug nuts). The spring mounts are good and the springs are not broken... I can't find anything wrong that could be making this noise? It's sounds really bad like metal striking metal and I'm afraid something is about to break. If anyone has an idea what this could be I'd appreciate hearing it...

[ThunderChicken]

If everything looks good on the outside, I would pop the differential cover and see if anything looks wrong in there.  I would also pop the plastics in the trunk and see if maybe there's something that came loose from the spare tire (I'm assuming the spare is in the same place as 4th gens as Thirds).