At first glance I thought I'd be able to help, as my Empeg is in a '99 Mustang. But I chose not to get the Mach 460 based on my thinking that I'd be adding aftermarket components, and I had heard the Mach 460 is extremely custom and difficult to deal with. If I were you (and I'd love to be you because you're driving an '01 Cobra
) I would stop by a local audio shop and tell them the story. They'll know the Mach 460 inside out, and should be able to tell you what you'd need. It's possible the amplifier takes 5-7V in, but there might be a preamp in there which takes 4V and ups it to the aforementioned 5-7V. This could be before or after all of the speakers are in the picture. Whatever the deal is, they should be able to help you out. I paid $40 for my install and it's flawless.