Geometrical stiffening of the panels via rib design are considered due to vehicle design requirement and vibro-acoustic considerations. This paper studies the damping effectiveness of different damping treatments (extensional, shear damping structural damping layer - based on friction and inelastic collision) for flat panels and geometrically stiff panels.This paper considers the significant panel characteristics, damping efficiency of extensional and constraint layer dampers and structural damping layer. The overall vibro-acoustic reduction is measured over the low and medium frequency regions. The damping effectiveness on the panels is characterized by average vibration reduction, and frequency response function (FRF). The in-vehicle damping performance is measured experimentally with vibration excitation on in-vehicle size body panels.