Strange rear left hatch noise
 

I can't describe the sound so I've added a video below to hear it, it's like a grinding/crunching/rubbing noise.

A year ago changed all suspension (Tein Flex Z) and full bushings (including all pillowballs (original mazda)). Spontaneously 2 months ago car started to do this noise when going over bumps, sounds quite aggressive... Doesn't happen when I go over drivers side (RHD), happens mostly when going over the left rear.

When the car is parked and I shake it (as aggressively as possible with friends), I can not replicate the sound, no matter how hard we push the car up/down.

Any help in which direction to look would be appreciated!

Have you tried checking it the Emergency Jack is secured in place?