In the interest of improved fuel economy, minimum weight design of the car structure has become a main concern for automotive engineers. In the outer surface panel, reducing the weight means reducing the panel thickness or using alternative materials. These changes will affect the dent resistance of the panel. In this study, the correlation between panel geometry, material properties and dent resistance is investigated. The approach is based on the relationship between the stiffness of a shell panel and the energy required to form visible dent. Mathematical formulation and design methods are presented that relate dent resistance to the design parameters of the various panels. The slam area of several deck lids and life gates are investigated and a dent resistance requirement is established. It is recommended that the outer surface panel (slam area) be analyzed early in the design process to determine its dent resistance, then the geometry of the panel can be improved or different material can be recommended to avoid adding slam reinforcement or increasing the thickness of the panel to prevent such a dent.