:lol: I thought X marked the spot!!
Just for everybody to know, I went to the auto parts store armed with info on both the horn and the bolt, and I believe he meant 16mmx1.0, not 6mm. That's what worked for me anyway.Based on the harness length, there are 2 threaded holes readily available to connect the second horn. (Both are 6mmx1.0) I chose the one nearest the front of the engine bay (arbitrary choice).