A support assembly formed by an additive manufacturing process using a printing head includes a trim member. A body includes multiple layers of at least one polymeric material applied onto the trim member via the printing head. The multiple layers each have multiple resilient polymeric material elements. A protective and abrasion resistant polymeric material cover is applied over the body using the printing head. At least one structural element is positioned in the body by operation of the printing head. At least one sensor is positioned in the body. At least one passage is formed within the body by selective omission of the at least one polymeric material from the printing head as the printing head displaces during the additive manufacturing process.