Quietness and shield feeling are one of the most important factors in the luxury of the vehicle. However, "Excessive Wind Noise" of a car is still a chronic problem in almost all OEMs and vehicles that is difficult to solve completely (TOP3 of 233 problems based on IQS_16MY). Although there's lots of factors, improvement in the door system is generally considered with increase of the W/Strip(thickness, size, etc.). However, the solution suffers from another problem of door closure, even if the cost & weight problem is excluded. Following increase of reaction load of the W/Strip will prevent the door from closing properly. Therefore, in this paper, we proceed with basic research to improve the performance of each of the door closing and NVH performance. Finally, we propose a design / material solution that considers both performance. 1) Characteristics of rubber Polymer materials including rubber need to define two properties of HyperElastic and ViscoElastic so that it's possible to analyze the characteristics of materials and construct analytical models. We have studied the material modeling method of rubber and confirmed the properties. 2) Door Closing performance In order to predict the door closing energy with W/Strip exactly, it's necessary to define damping effect because the velocity values are different for each section position. So ViscoElasticity was applied for implementation in anlysis with actual door closing condition. 3) Sound Transmission loss improvement Based on the theory of acoustics, the evaluation with materials is carried out first. We confirmed the sound absorption / sound insulation performance of various rubber and confirmed how to improve the performance. We have implemented the analysis in the unit of section, and confirmed the improvement direction of the soundproofing performance.