A method of joining a first piece of an automotive component that is made from a first material to a second piece of the automotive component that is made from a second material includes machining a fay surface onto each of the first and second pieces of the automotive component, cleaning the fay surfaces of each of the first and second pieces of the automotive component, placing a metal filler between the fay surfaces of the first and second pieces of the automotive component, holding the first and second pieces together with the metal filler positioned between the fay surfaces of the first and second pieces, and passing an electric current through the first piece, the metal filler and the second piece to melt the metal filler and weld the first piece to the second piece.