We then secured the lower section of the box in place. Every car is different, so how you bolt in the box will vary. In our case, we used two small plates under the trunk floor to tie the bolts into the car's frame. This provided more stability than just anchoring the box to the trunk-floor sheet metal. Also note the back panel of the box. It's designed so that the hole for the battery cables can easily by rotated to any of four positions.