OK... Updates
I purchased an MDI (GM Scantool)chinese knockoff and a subscription to Acdelco TDS for the software to play with
After a lot of trial and error I can scrub a car to no vin security ...bascially same as it powers on when being built. I cant change the srs module as supplied software lacks the ability to remove the security in the factory software for vin removal. At this stage without further developement if you wanted to do what ive done and change config with vin changes, you would have to buy a new srs module or put up with a couple of error messages present in the body control module but showing no airbag light. Dont try to program tne srs module to a mismatched vin as it kils it...After scrubbing the security I can then change the vin in the bcm and re-pair the keys. Then program all the modues to the new vehicle including front view camera and hud. This enables the features that the cars was built with provided there are no hardware mismatches from changes in production... I was lucky an noproblen with the vin i chose... Try one with very similar build dates...
I have successfully converted the SS electronics I had to be that of a Calais V installed it all in a VE Shell with a 3.0litre v6 I hade with modified Evoke wiring. I modified the 3.6l tune with HPTuners to work with the 3litre engine and correct the lack of alaternate fuel capability of the smaller motor by turning oof the fuel comp sensor low frequency mil nd error. My car now has all the calais v functionality including keyless go, rainsense wipers, lin bus windows, hud, frontview camera with gap alert and lane departure warning.... all working and all full factory updated programming. Albeit with the vin from a Calais V Sportwagon I found on Car Sales

.... I have all the immo functionality working correctly. I updated the radio to get rear view camera lines and all the current fixes and features including better sound it seems.
If you wanted to do the TPMS thing you could do a Conversion to the Craig Lowndes VIN but there would be warranty ramifications for that sort of behaviour I would expect. Until I actually have time or the willngness to sniff the packets and reverse the protocol this is the only wy to get TPMS Working I can do. Tazzi hasgone quiet, it seems, on the VF Stuff
Unfortunately with the v6 there are differences to the Brake Vacuum sensor in the v8 ecu so I cannot enable TPMS in my vehicle at this stage.
I have worked out how the instrument cluster does the images for door open etc. All images are not stored in the cluster at once. If you install and "Pair" a wagon cluster to a sedan it will say "rear access open" when the bootlid is open and vice versa. It appear from my testing that a sedan vehicle will operate the wagon module for rear wiper and tailgate operation succesfuly.
For the GTS I can remove the security, program the cluster as a wagon using a Clubsport Tourer VIN and then Pair it back to the sedan BCM. This will not resolve the images on the GTS MyLink for edi and parking sensors but that is not the end of the world. I may be able to program the EDI as a wagon but until that is all together I wont know. I dont want to it show as a Clubsport or remove the accssr to the MRC so I will leave well enough alone and put up with the incorrect pctures.
I know this is now possible and have the procedures to make it happen without concern.
I got all the wiring diagrams from the acdelco tds website to /make this all happen as well....