This should serve as a tool to help all others.
2004 Sierra with bose, xm, and onstar.
Amazon.com: SWI&PS - PAC Steering wheel control interface for Pioneer and Sony NEW Version 1.6.8 with Bluetooth: Car Electronics
In-dash Receiver Kit Fits select 1995-up Buick, Cadillac, Chevrolet, Geo, GMC, Hummer, Isuzu, Oldsmobile, Pontiac, Suzuki & Toyota models — double-DIN at Crutchfield.com
GM Factory Integration Adapter General Motors Class II data bus interface — retains OnStar system, factory door chime, and Bose system with aftermarket radio at Crutchfield.com
Am I missing anything?
2004 Sierra with bose, xm, and onstar.
Amazon.com: SWI&PS - PAC Steering wheel control interface for Pioneer and Sony NEW Version 1.6.8 with Bluetooth: Car Electronics
In-dash Receiver Kit Fits select 1995-up Buick, Cadillac, Chevrolet, Geo, GMC, Hummer, Isuzu, Oldsmobile, Pontiac, Suzuki & Toyota models — double-DIN at Crutchfield.com
GM Factory Integration Adapter General Motors Class II data bus interface — retains OnStar system, factory door chime, and Bose system with aftermarket radio at Crutchfield.com
Am I missing anything?