Something loose under car?

[2011x5]

So i got my car new 4 tires and they did an alignment when they did the tires. Few days later car started to make some sounds like something is loose under the car, sometimes it comes from the middle of the car sometimes from the back. This happens only on uneven pavement and bumps. Went back and changed the tension struts and front sway bar end links and still have the sound.

It sounds like some bolts are loose and its like a metal sound it kind of rattles on bumps and stops on even pavement.

Checked the trunk and lower hatch its not those so we can eliminate that. Also checked the drive shaft seems tight no play.