Damping materials are used to control vehicle noise and vibration. This paper discusses techniques to design effective vibration damping treatments. Vibration and damping characteristics of vehicle panels with viscoelastic layers have been investigated. As a result of the investigation, new parameters have been contrived. Applying the parameters to basic theories, it has become possible to estimate the damping efficiency of complicated body panels and to design the panel structures to maximize the damping effect. Criteria for the determination of the body panel specifications and methods to control resonant frequencies of vehicle panels are also presented. This paper concludes with applications of the damping techniques to reduce interior noise.