I'm looking for a wiring harness to replace the stock head unit. I have the Audiophile/Mach (whatever it's called) head unit with the stock sub and amp. All the harnesses I've seen for a 2003 have a different connector, the ones I saw have a more flat main connector, while mine has the rectangular one, here's the front and back of my head unit:

The middle connector isn't used, I'm pretty sure that for a CD changer.
This is really confusing me so could somebody point me in the right direction?

 

any harness will fit the problem is that factory amplifier with the subwoofer is not going to work
(last small plug) there is no harness for that