This disclosure provides a door lining upper base and a method of manufacturing the door lining upper base through injection molding of several sub-components. The door lining upper base is manufactured by separately injection molding a base substrate that forms the structural shape of the door lining upper base including aesthetic curvature, and first and second support structures that include attachment mechanism for connecting the door lining upper base to other aspects of the motor vehicle. In this way, each sub-component may be injection molded in a cost effective manner using a two-piece mold without the need for complex multi-part molds including side-sliders or lifters. The resulting door lining upper base therefore includes an aesthetic curvature, while still being manufactured in an efficient and cost effective manner.