In this study we are going to measured and analyze solar exposure in the interior part of three different car and the aim of this study is assessing the correlation of Natural and Artificial weathering with degradation of some polymers like PC, PMMA, PP, PS, PET which are the most used inside of these cars. In the first part of this study, we have short summary about the effect of solar irradiation (specifically UV wavelength) on some specific polymers so we will see some definition like Irradiance, Illuminance. With some International standards and special equipment, we can have artificial solar irradiation, subsequently we are going to see the effect of NATURAL and ARTIFICIAL weathering to different polymers.