I cant answer the question with regards to the 06 or 07. My guess would be that it would not be that easy, but I cant say that with any assurance. However, it could be that the adapter I have may be from something like that, I dont know for sure. Then with regards to the FOB's there would be the question of whether they would work as well with an older Body Control Module.
Essentially there are a lot of unknowns. If you are able to transplant one from a newer vehicle please report back here as I would much rather have a factory set up than an aftermarket one.
For the sake of production ease and costs I would say the odds are that you the harness would have everything in it and you would just have to have all the components but the question then becomes how much of the harness are you going to need. Is it sectionalized so that you can just pull one part or are you going to need the entire harness. If its the entire harness your looking at a lot of trouble pulling it and reinstalling it and in that case it would seem easier, to me, to just get the same adapter I have and work from that.
