Those boxes are prime targets for storing your electrical repair gizmos. Load it up with your soldering irons, shrink tubing, crimp connectors, spare DVOM, wire stripper, wire loom sheathing and you are set to drag that out to the repair project with no return trips to the garage needed.
I have a second version holding the pop rivet collection/wire ties and an assortment of hose clamps.
Your mileage may vary.
<edit> I guess I was missing the key word "lightweight" in describing the box contents. But I guess you knew that already.