You have a factory system that is 6 or more speakers, and have an external amp that handles the crossovers to feed the tweeters. Re-wiring all of this without keeping the amp is a royal pain! These directions allow you to replace the head-unit while maintaining the factory amplifier and speaker wiring. ZERO re-wiring to the speakers is needed.
MVS Forums member kcodyjr started a topic years ago that now contains a trove of excellent Volvo P80* speaker information: I’m doing the upgrade to my 1996 wagon and my 1997 sedan. I’m unsatisfied with any amount of cutting and hacking, so I’ve tracked down some (alleged) adaptor brackets: Autoleads SAK-3211 – dash tweeters, 36-56mm Autoleads SAK-3204 […]
Also note I said ‘certain phones’. You need to make sure your phone has been tested & certified by Pioneer. It requires an MHL or HDMI connection as well as a Bluetooth connection and a few apps installed. Since I don’t have an iPod, I’ll focus on my Evo 3d. I should note that my daughters do have an iPod plugged into the unit but I never use it.