:The use of lightweight reinforced RIM composite substrates is increasing globally with primary focus on interior door panels, instrument panels, and package shelves. Each of these automotive interior applications has unique performance requirements. This paper will describe advances in polyurethane chemistry and low cost fillers suitable for current fully covered interior door panel production programs. Advances in polyurethane chemistry include improvements in polyurethane release characteristics from the mold by incorporation of internal mold release agents. A 7-10 % reduction in raw material cost is achievable by using low cost fillers, such as wollastonite, yielding mechanical properties essentially equivalent to door panel substrates utilizing fiberglass mat reinforcement. A method of obtaining value by recycle of in plant scrap and trim into like products will also be reviewed.