It is normal for there to be a space at the back of your PlanetBox Rover, Launch and Shuttle.  It is an intentional part of the design and allows the box to accommodate the Dipper(s). The back of the lid does not need to be flush with the tray. On the Rover, in particular, the rear right side (when looking at the back of the lunchbox) is slightly lifted. The metal rod in the hinge does not extend from one rear corner to the other. The rod resides only inside the metal sheath.