My dealer replaced only the head unit because of my persistance in get the RDS to work (see other forum post for this mess) so I did not get the addition of the two rear deck speakers. I am however adding a custom sub box and amp as well as replacing ALL of the speakers in the car. Even though the system sounds pretty good, it is not quite what I want and since I like stealth when it comes to high end systems, I will be leaving the head unit in place and just adding everything else. As far as all of the other posts since my last, I agree with just adding to the existing as far as cost. I was just fortunate enought to get my dealer to replace the unit under the pretence that the manual said I had RDS but infact I did not. Boo bad misprinted manual, Horrayyyyyy Beeerrrr