A plastic assembly having a permanent mark therein at a subsurface location and formed after substantial manufacture of the panel assembly. The plastic panel includes a substrate and a coating over the substrate, the coating including a surface that defines an exterior surface of the panel assembly. A mark is located beneath the exterior surface of the panel assembly. In making the panel assembly, a plastic substrate is provided and a protective coating is applied to the substrate. After the step of applying the protective coating, a subsurface portion of panel assembly is exposed to a laser light. The laser light opacifies a subsurface portion of the panel assembly, thereby rendering the mark within the panel assembly.