Here is the Metra Kit I have. New Open Box, never installed.
Has remote DIC, Double Din Radio Mount, and harness. This kit allows plug'n play to retain Full factory features (except steering wheel controls, need additional module for wheel controls) but should retain OnStar and RAP. Harness is about 3 foot long so you can remote mount the DIC in glove box or center console.
I was going to extend the wiring and build a custom overhead console to mount the DIC overhead, much like the W body cars had in the early 2000's.
Now that I did the cluster swap I won't need this anymore. I will just go out and buy a Double Din radio mount.
Let me know if you are interested in the kit. I will sell for $100 including shipping to 48.
Here are a couple pics of the kit I have.
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