During the past 15 years, glassfiber mat or preform impregnated with polyester resins have been compression-molded as exterior panels for a complete plastic body or for individual body panels adjacent to steel panels. The recent introduction, however, of new, smooth surface, glassfiber reinforced polyesters, particularly bulk molding compounds, has accelerated the use of these thermoset plastics as a replacement for painted zinc die castings. These new type compounds can be molded into parts that are substantially void of sink marks, readily paintable with little or no sanding, and able to withstand present production and repair paint oven temperatures without cracking or distortion. Volume use in the future depends on the success of current production experience and projected economic savings.