Anyone know if it the wiring is pre installed to add the factory sub system to the factory base stereo with sync? I replaced my stock door speakers, but that little extra kick might be nice. If it's possible to plug and play, it might be worth looking into. I have zero interest in running an aftermarket amp, and sub. I know that I would get better results with an aftermarket system, but I figure these things have been around long enough that I should be able to pick up the factory sub/amp assembly from a wrecker for pretty much nothing.

Is the wiring even back there? Is the base head unit set up to run the assembly, even if the wiring is there?