I was wondering if anyone else with their new ford F-150 can look out their rear view mirror and see the box vibrate on one side, it's on the drivers side, it's like the springs or shocks or something just isn't the same on that side as the other. If you open the back window you can hear it, really weird if anyone knows what it is please help

I'm pretty sure the bed is loose, it shakes so much you can hear it rattling!