Is there a way I can move this to the audio section

 

I'd call Crutchfield and see what they suggest. Their tech support is one of the best I've ever dealth with.

 

The wiring is all different for the Mach systems. If you are going to do any serious radio mods to a Mach car the first step is to legit rip ALL OF IT out and run new wires. Not super hard on a Mustang but still a pain. Why I prefer non-mach cars... and my current car is a Mach car lol. Just going to do a good double din HU and leave the rest of the Mach stuff in there.

 

In the mach systems the tweeter is actually a full range speaker. If you want to remove the whole mach system without running new wires use the tweeter wires to new door/deck speakers as the full range sound is powered from the deck and not the amps in the back. I have done a few and it's not that hard to bypass the mach system completely!

 

I did not know that... was unaware of this shortcut. Anything like that for the back? Way easier to run wires in the back tho... Doing a new Pioneer deck next week and keeping the Mach system for now but its definitely not optimal and starting to kick around just some good 6x8s and gut the Mach tweeters/install better tweeters up front, a good budget speaker amp and a 10" sub to a kicker 500:1 mono amp I have lying around. Also putting the battery in the trunk finally.

 

I was looking at the wiring diagram for it and it likes there are 6 amps total. It appears to me that when you push the Mach button on the radio it turns the 4 amps in the trunk and the sub-woofers on. It looks like the amps in the trunk are for the sub-woofers only. I am going to try and unplug it and see if all the stuff in the interior keeps working. If it does the trunk amps and sub-woofers will be coming out. I don't want an aftermarket radio so that option is out.

 

+1 for full replacement. Even Crutchfield's article says the Mach systems aren't ones you can typically add a piece at a time.

I'm in the process of doing this myself on the Mach 460 system; a blown door speaker finally got me irritated enough to pull the trigger on some components, a 5 channel amp and a 10 (I already have a Kenwood head unit that will work for a while). I personally hate hacking up the factory harnesses, so I did make it a bit more difficult on myself and ran all new wires.
Running from the doors actually wasn't as bad it seemed; used a set of wire fishing rods and just carefully worked through the rubber boot. The opening on the inside is a little small, but it's definitely doable.

What complicates my situation is the rear deck; once you pull the amp/speaker rack, there's nothing there to bolt anything to. So, I'm in the process of building one (carpet wrapped MDF, like a typical subwoofer box).

 

For me, hacking up the factory wiring just feels wrong (like fixing something with duct tape and zip ties). Plus, if for some odd reason I ever need to put the Mach system back in (however unlikely), I have the option.

As for mounting, I took the entire amp/speaker rack in the rear out (I'd have had to modify it anyway), which left me nothing to mount speakers or an amp to. I'm almost done with a replacement piece that I've left space to mount my amp/crossovers on the underside, but for just adding an amp to the Mach system (retaining the rear rack), I can definitely see using the back of the rear seats.

 

not sure about the back, I've always sold people on good components for the doors and a sub in the rear.... I plan on removing the mach system from my car in the future and I'll check when I pull the subs out of the rear