installing after market radio, which interface do i need?

[sweetmamah2]

So I am bidding on a 06 Nav system on Ebay. Will it fit and work on my 03

[ffl]

i got my kenwood allready in january, it is a dnx8220bt.

i wrote some mails to pac and also metra. it looks like pac doesn't have an interface for my hummer that retains the factory chime. but the metra axxess gmos-04 interface should work, referring to metra. the interface retains the factory chime, with or without onstar, as long as it's a factory amplified system. and i have an amplifier under the central console for sure. thanks for the infos.

[pwrhse2k]

The gmos-04 interface is a piece of crap! Lots of speaker pop and alternator whine. I have the Kenwood 7100 Nav and will be pulling the gmos-04 interface and bose system out and wiring up aftermarket components. I'm yanking the onstar and don't give a hoot about the door chimes. I want to hear good quality sound coming from the speakers and you definitely don't get that with the interface installed. TRUST ME!