Abstract: A hinge and connection assembly kit is used in combination with an open vehicle box covered by a cap or topper and having a pair of opposed parallel sidewalls, each with a channel rail along the interior of the upper edge of the sidewall. The vehicle cap for covering the open vehicle box also has a pair of opposed parallel sidewalls, each of which has a base rail along its lower margin for resting on the channel rails of the vehicle box. The kit comprises a plurality of hinge connection assemblies connected between the channel rails of the box sidewalls and the adjacent base rails of the cap sidewalls. Each hinge/connection assembly grasps the channel rail of a box sidewall. A lower hinge plate is connected to the channel grasping structure and has a first, downwardly concave hinge channel at its outer edge. A corresponding upper hinge plate is connected to a cap base rail above the lower hinge plate.