I just recently purchased a 2002 Nissan Xterra with the "base" 100w stereo. I have come across a 2001, 6 cd factory stereo for sale. In trying to keep things relatively stock, will this stereo (2001) match perfectly in my 2002, I mean just unplug the harness from the old stereo to the 6 cd stereo/changer? In addition, I see that the Rockford Fosgate is an option for the 2002, is the amp "built-in" the stereo, or have separate amps for the stereo? Thanks for all your help! Jim