The quest for weight and cost reduction of automotive components without changing their quality and performance is a constant concern of suppliers and automakers around the world. When dealing with products related to the internal insulation of the vehicle this concern is even greater since the evaluation of acoustic comfort is a factor of growing importance for the acceptance of the automobile by the final consumer. Based on it this paper aims to evaluate the acoustic insulation of the dash panel of a passenger vehicle and propose an alternative approach to mass reduction of this component by applying layers of sound absorption material inside the instrument panel. Using analysis of particle velocity and sound pressure level inside the vehicle, a comparative test was performed. It was found that the lack of insulation due to mass reduction can be compensated by addition of a high absorbing material on the instrument panel, thus reducing the noise transmitted through the instrument panel without compromising the acoustic performance.