Unused 4-pin connector in driver's side trunk
 

Alright, starting off with some basic info. I have an 09 Lancer ES, without the Sun and Sound package. Where the factory sub goes, under a little flap in the trunk lining, there is a 4-wire pigtail taped back on itself. Is this the connection for the stock sub? If so, does anyone have a wiring diagram of what each wire does? I am going to be adding an aftermarket sub and amp, but if I can do it without modifying the existing harness, I'll do that as much as possible.