stock 2006 impala radio bench test

Hi
New to the forum as you can see, been looking at stuff around the site for some time now, so now it's time to post.

So, I have a project here, for which I can't seem to find much help, even though I've tried searching for weeks, with almost no useful info.
I have the stock radio out of a 2006 Impala, it is the "Up level" unit, which has 1CD, MP3, Aux, and supports some other features as well, it's model No. is: 15887275.
The idea is to make this radio work outside of the car, and ultimately installing it into a much older GM vehicle which does not have any computers or as a matter of fact anything digital in it at all.
Now, from all the info I've gathered, the radio can work only with the GMLAN bus attached, on which it receives the commands to turn on, verifies the stored VIN number and compares it with the one located in the BCM (to make sure it is in the same vehicle), and generally acts as a part of the car's systems.

I have heard that some of those units can be bench tested and powered at least for some time without being attached to the car, any info on that perhaps? 
the ultimate idea for me would be to just make it work completely independantly.

I have powered it up from a 12V supply, and it only shows the clock if you press the info button, and will also respond to pressing the eject button by saying "No CD loaded"(or something similar).

I have gone to the extent of getting a separate BCM module out of another 2006 Impala from a local salvage yard, but it is not the same car so the VIN would be different.
If the only way to use this radio would be to have it connected to this BCM, then I am willing to go that route, if only I had the knowledge on how to properly do that.
By the way, I have the wiring diagram of that BCM (pinouts for all of the connectors), as well as wiring info for the radio.

So, any help with this would be much appreciated, I know this is something quite out of the ordinary and not at all simple in any way, yet I am quite familiar with electronics and somewhat with car set ups, and I am willing to go through the effort that is needed to make it work, if there is a way which is not extraordinarily difficult.

I really loved the design of this head unit and it's features, appearance, and it's VFD display. It's abundance also makes it a good candidate for experiments and modifications, so please don't start with the "go aftermarket" connents...

I'm attaching a  few pictures so you can see what it looks like, as well as the pinout diagram of a similar unit (can anyone verify if the pinout is correct? -it is in fact from a SAAB head unit, yet they have a similar connection).

Thanks!

Thanks for the input guys,
Sparkie, Judging by your suggestion, I see that you have some knowledge regarding the GMLAN bus:
If you say that a pulse should be sent to the radio every 10 seconds, so aside from that, wouldn't the VIN verification against the one stored in the BCM be required?
Anyway, I think creating a circuit to emulate the signals from the BCM would be somewhat sophisticated, so if the only way for this radio to work is with the BCM, then I'll have to set up that BCM I have (or another one) to do this...
So, if I choose to go this way, a few questions arise: Let's say I've programmed the BCM and the radio to have the same vin, Will the BCM allow the radio to work without disabling the security, meaning making it work somehow without any parts of the ignition system attached (key cylinder, transponder), or if not, then if I'll have to get the ignition parts and the key, how will that work, does a key programmed to work only with the same BCM in the car it belongs to, also is there any key/transponder relation, or is all of the programming in the BCM?

Gerring some wiring diagrams for this car would really be helpful too...