AUTOMOTIVE PANEL STRUCTURE

In order to increase road noise transmission loss, a double-wall panel includes a core material. The core material is enclosed between an outer wall and an inner wall facing each other, and has at least a predetermined thickness across the panel in all in-plane directions of the walls. The core material has a specific surface area of 20,000 (mm/cm) or more, where the specific surface area is defined as a surface area per unit volume.