Abstract: A spring designed to be mounted adjacent and in conformance with a convex or concave surface that has varying radii of curvature. The stiffness against bending of the spring varies along its longitudinal axis. The stiffness against bending of various portions of the spring is proportional to the radii of curvature of portions of the surface adjacent which each portion of the spring is to be disposed. The mounting structure for the spring includes female mounting members that are to be engaged to male mounting members. The female mounting members and male mounting members can be engaged to one another by sliding the two components together. The spring and mounting system are particularly well adapted for holding objects adjacent an inner surface of body panels of a vehicle.

Abstract: A door-activated retractable step for a truck includes at least one step cavity disposed within a side wall structure of the truck in proximity to a door thereof. An extendable cover for the step cavity housing, when closed, creates an aerodynamic continuation of the side wall structure containing the step cavity. The cover is pivoted about a horizontal hinge in response to the truck door being opened to form a continuation of the tread surface, creating a wide step.