Car Stereos: Cd player, vehicle data bus, party interface

Question
Recently I went to a local place for car audio. I asked about putting a new screen
in and they said I would have to purchase a $200 part just to change out the
screen in a 2008 G6. Is this correct? If so why is this part needed?

Answer
Hi Ben,

Lately, the trend in new vehicle manufacturing is to integrate the factory radio with vehicle's computer system.  GM has been treating the factory radio as an integral part of the vehicle, rather than just an accessory; in the G6, the vehicle information center and display is often built into the radio.  After-market head units can't communicate with the vehicle data bus, so a 3rd-party interface device is usually required, especially if you want to keep the information display or other features like Onstar.

From the price of the part, it sounds like they're talking about the Metra 99-3303 kit (or something similar).  This has a built-in view screen, as well as a module capable of interpreting and communicating with GM's LAN-bus system, so that all the factory functions remain intact.  

The 99-3303 is made for single-DIN head units, so if you're looking at a full-size (4"x7") video head unit, you wouldn't be able to use it anyway.  In this case, you'd lose your information center display.  If you don't mind losing the display, you don't really need the 99-3303 kit; you can get by with a standard mounting kit (99-3302 or 95-3302), an antenna adapter (40-GM10) and an adapter harness (XSVI-2103NAV).  

Hope this helps!

Brian