A hardtop turns a convertible or roadster into a genuine coupé. It reduces interior noise and aerodynamic drag, and offers the best possible protection against bad weather. The hardtop for the Audi TT Roadster’s, for example, is built on a stiff aluminium space frame. This frame forms the supporting structure and supplements
body stiffness. The hardtop’s outer skin is made of a plastic material. The TT hardtop provides good insulation and has a glass rear window for optimum visibility to the rear.