I did get around to finishing the sunken battery box in the trunk. Actually, the hardest part was getting the insulation/sound deadening back off the trunk floor where I wanted to put the box. I am using a side post battery and after setting it in the old Porter Cable tool box I had a couple of inches excess height so I squared up the box and cut down into the four corners one inch. Bent the edges over and shot a coat of self etching. The rod in the picture is used to hang the box for paint. I will close off the holes I drilled when I was going to set the box above the floor later. I marked the trunk location for the box drop in, cut the hole 3" smaller on each side, angle cut out to the edge of the box size markings and bent each side down do I had extra support on the side. I will spot weld these to the sides of the box as well as the tabs on the box to the floor. This may seem like overkill but the battery weighs 50 lbs. so better safe than sorry. Drilled new cable holes in the front end of the box, dropped it in and spot welded it in place. Plugged the original bottom cable holes by adding two straps on the underside for added support and added another coat of primer. Then I glued a 1/2" piece of insulating rubber along the eventual terminal side to prevent arcing. The box had a 1/8" lip on three sides at the top so when I bent it over I had a retainer for the top I made out of 16 gauge. I thought about putting a couple of beads in the top but it seemed pretty strong so I left it. A sheet metal screw in two of the corners should hold it in place.