I see a lot of threads asking about what to get to install a new head unit so figure we should make a sticky with all the info.
This will be updated as you, the experts, give more or correct my information. It has been years since I done one of these and I know products have changed. If you have a suggested part that you feel should be added please provide as much information and a link to the manufacturers website for that part.
Disclaimer: This is in no meant to be completely factual posts and all viewing are encouraged to research and ensure fitment on your vehicle.
OS-5 - OnStar® Radio Replacement Interface for Select 29-bit LAN General Motors Vehicles with or without Bose Sound System. Retains OnStar® system functionality and the Bose factory-installed amplifier (if present) when the factory radio is replaced in a 29-bit GMLAN vehicle. Generates all safety warning chimes and audible turn signal indicators.
GMRVD - Overhead LCD Retention Cable for GM Vehicles With Rear Seat Entertainment. Provides an audio/video signal output from a factory radio to an aftermarket monitor. Also for use with a radio replacement interface to retain the overhead LCD monitor and IR system.
95-3305 - GM Dash Kit
GMOS-LAN-01 - GM 29 Bit LAN Data w/RAP ACC & Onstar & chime retention
GMRSAV - Factory rear seat entertainment retention harness for GM LAN29 vehicles
GMRSAV-2 - GM 12+ w/Nav RSE A/V Harness
BACKUPCAM - Factory back up camera retention harness for GM LAN29 vehicles
BACKUPCAM-2 - Factory back up camera retention harness for GM LAN29 vehicles with factory navigation
Maestro RR - Web-programmable radio replacement interface for integration with factory systems including steering wheel controls, media player, hands-free telephone, voice commands, and satellite radio modules. Also displays vehicle information (performance gauges, climate controls, battery voltage, check engine codes and more) with iDatalink-compatible radios. Basic radio replacement features also available with non-iDatalink-compatible radios.
AVGM5 - Provides A/V connections to the factory video screen and A/V input port.
This is an on going thread that I will update as I can.