Knowledge of the damping properties of a windshield is a fundamental element of the acoustical characterization of a car.The measuring method of damping for a windshield is presented in the paper. The damping loss factor -as a basic measure of mechanical damping -was determined experimentally by two means: the reverberation time from impact hammer testing as well as the modal behavior from 3D laser scanning vibrometer measurements. The results proved that the modal shapes have a fundamental effect on the measured damping values.