squeaks over bumps

Sounds like dry joints? You might try spraying the underside/under-carriage with something like this:

When I was a teenager living back in the UK, I worked at one of the local garages and they would use waste-oil to spray on the underside of squeaky cars to quieten them down, and also to act as a cheap under-seal! (…just sayin' )

 

I'm skeptical that it's the shocks on the hatch.
First of all if the hatch is closed, going over a bump shouldn't really stress the closed hatch's shocks.
Secondly, I would assume that if those shocks were making noise, you'd hear it every time you opened and closed your hatch.

Which by default leaves you with suspension parts that might need lubricating.
Hope it's that simple.
Because I had an Older Honda Accord with this symptom and it was the CV joint and boot. Which was a pretty expensive repair.