If you are looking at the Pioneer adapter kit from treuillonaire then get it.
He's a member of this forum and his kit is awesome and specially designed for our cars.
Do you have a Bose rear speaker unit or a non-Bose unit? (they both have different wiring)
I am driving the front and rears from the Pioneer AVIC and the door speakers from the 4x40 OEM amp.
But it was a little tricky to get it to work.
I can give you more details if you're interested
I am ready to do the same thing can you please give me the details on what you did. Thanks!!
The CDR220 is not that bad...until you turn it up. My 1964 Chevelle on AM with a Reverb unit attached to rear speakers sounded awesome to the Becker unit.
Old Hippie Young Heart
2000 S/3.2 Liter/Tiptronic/Boxster S Sport Package/Cruise Control/Slate Grey Metallic
Red Special Leather Interior/Red Floor Mats/Red Hand Painted Instrument Dials/Roll Bar/Windstop
Small Carbon Package/Leather Wrap Carbon Wheel/Center Console Exterior Color/Alum Carbon Shift Knob
AM/FM Radio w/CD Player & Changer/Digital Sound Package/18" Turbo Wheels/Wheel Caps w/Colored Crest
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I still wave at Boxsters, but they no longer wave back :-(
2002 Boxster S "Violet" (sold but not forgotten)
2009 Carrera 4S "Kelsey" (current ride)
2015 FIAT 500e "Nikki" my commuter car