The BMW 3 Series E36's boot spoiler consists of high-pressure Hard Polyurethane (not Polyester). This material is both durable and costlier than others, making for a snug and superior fit. Each spoiler is carefully crafted in aluminum molds for optimum quality and endurance during mass production. It endures rigorous testing in high temperatures to ensure durability and aerodynamic efficiency while boasting meticulous design. The un-primed product will require priming and painting in your desired color.