A structural body of a vehicle can comprises: a hollow metal component comprising walls that define a channel, wherein the metal component has a metal component length, and wherein the metal component is selected from the group consisting of beam, rail, pillar, chassis, floor rocker, and cross-bar, combinations comprising at least one of the foregoing; and a plastic-metal hybrid reinforcement having a cavities therethrough, and a metal support having greater than or equal to 3 walls forming a support channel. The plastic element is located in the support channel wherein the reinforcement is located in the component channel.