A gas assisted injection molded part includes internal cavities extending between two surfaces of the part. The cavities are plated for electrical conductivity after a surface cleaning and etching process. The part may be an automobile instrument panel wherein the internal cavities are plated to create a series of "bus" conductor lines. These lines carry power, ground and/or electrical signals over relatively large distances, allowing other components to attach at points along the structure eliminating the need for discrete wiring and wire harness interconnect assemblies.