The JASO M351-1998 standard specifies the method of weathering resistance testing for exterior trims of automotive parts using xenon arc lamps. The standard uses xenon arc lamps to simulate sunlight exposure to evaluate the durability of exterior trims such as body paint, plastic parts, etc. in the natural environment. The test includes the color of the material, Gloss and other performance, which is designed to ensure that the exterior parts do not fade and lose of gloss during long-term use. It is recommended to check if there is an updated version to get the latest test standards.