Rear popping noise
First, I have a 2009 Mazda 3 Value Edition. No mods, 75,000 miles.
I have a popping sound coming from the rear suspension (both sides but driver side more often). I can't for the life of me figure it out. I know these things are hard without being there but hope someone with experience on these cars can help. It happens on a regular basis if the outside air temp is 65* or lower. It gets worse with colder air. Above 65* it's really random. Conditions I normally hear it are: going over small bumps, heavy braking, medium accelerate (after heavy braking), cornering (left or right less than 25 mph), and sometimes under random conditions. The popping ranges from soft to loud and sounds as if it is coming from the trunk.
Things I've done:
Removed all items from trunk (e.g. jack, spare tire, etc.)
Replaced sway bar end links - didn't help
Removed sway bar completely - didn't help
New Shocks (noise was there before) - still there
Replaced upper shock tower mounts - didn't help
Double checked shock mounting bolts for tightness - all tight
Used GoPro to to record suspension, no visible issues
Checked all rear bushings, they look okay but maybe not???
Thank you in advance