This paper explores the performance of light weight attenuators, which take a dissipative approach to sound abatement in the motor vehicle. An analytical model is used to predict the sound transmission loss and random incidence sound absorption of attenuators, absorbers and sandwich insulation systems. Then, a mathematical expression is developed which combines the dissipative and sound transmission loss performance to determine the total noise reduction provided in the vehicle. Using this equation, the performance of multi-layered attenuators is shown to be comparable to, or better than that of sandwich insulators. Finally, test results from various studies in vehicles show that significant weight savings can be realized by using these multi-layered attenuators, which take a dissipative approach to vehicle sound insulation, rather than the traditional sandwich insulation system.