Components to provide instrument panel system structure have typically involved the use of steel, magnesium or aluminum or various combinations of these materials. Some concepts have also involved the use of plastic components to provide partial system structure. Most of these concepts have required the use of additional components to provide for air distribution ductwork.The concept which is the subject of this paper is the use of a composite structural plastic beam to provide total unassisted system structure while also providing HVAC air distribution ductwork. The analytical models used to develop this system will be described. Test results will be presented for actual injection molded and assembled composite beams and compared to those predicted by the analytical models.