An automotive component including a composite casting is provided. The composite casting includes a steel member and an end cap fastened to an end portion of the steel member. A cast coupling member is cast about the end portion of the steel member including the end cap, thereby positively and rigidly securing the cast coupling member to the steel member. The automotive component can comprise an engine cradle, a control arm, an instrument panel support structure, a bumper assembly, or a twist axle. The cast coupling member is typically formed by casting-in-place aluminum about the end cap and the end portion of the steel member. The steel member is typically a tubular member, and the end cap typically includes a flange designed to provide a mechanical interlock surface with the cast coupling member. For example, the flange can have a polygonal shape, an outwardly extending member, or notches.