I have the 9 speaker system (factory). im wanting to know if these are enter change able with a newer model 9-5. mainly one with an Ipod hook up. if not i guess i need to purchase another unit in order to play my Ipod. (without radio waves). Then the next question is. do i really need a tech II in order to remove and install my new stereo. I usually remove a factory unit, put in an alpine and walah. Im hearing with this saab, the radio needs to be divorced. plz inlighten me