Significant effort has been expended to improve the sound made by a closing car door. This study focuses on reducing door glass rattle sounds, not only evaluating the rattle influence of door glass support but also introducing an approach to reduce glass rattle noise by using sealing components. The first part of the study is dedicated to minimizing vibration. A jig is constructed to evaluate the influence of a door glass support on the rattling. The jig is employed so that the glass meshing between the A and B pillars can be controlled; the glass holder moves in the x- and z-directions and the belt molding moves in the y-direction. An impact hammer test was adopted for investigating door glass rattle. The frequency response obtained via impact hammer testing is analyzed by varying the glass support points and important factors that should be considered in early design stages are obtained. The second study is about optimizing vibration absorption. A glass run, door-side weather-strip, and body-side weather-strip are used to absorb vibration. The glass run section is created through the TRIZ technique. Performance evaluation of the rattle in this section show that the damping speed improved by 35% compared with the damping speed of the existing glass run, rendering it possible to significantly reduce glass rattle noise. This study suggests an approach to reducing both the vibration caused by DR BIW and door glass rattle noise using weather-strips. This research also shows that the door-side weather-strip is the most useful in reducing rattle noise. This study provides greater insight and access to the door glass rattle problem.