I am not sure about the rental agency or business ownership. I was able to find minimal information about the XM module being standard and that is a negative. I have a base 06, and it was apparently optional. Like I said I do have the band button, so according to the info that I found I should be able to get the module and plug everything in and be done. On the flip side, I have found the TERK connector (basically the same thing)for GM vehicles that is supposed to work as well, looks like that will be cheaper. Used factory modules are not as cheap as you would think they should be and it appears you have to have the dealer flash it or something for use. Right now the real problem is that I cant seem to find a definitive answer on anything. I wish I could just find someone that says "buy this, its the cheapest method, you can keep factory look, and it will work" lol. All of the input is helpful though, at least it is giving me ideas to search for. Right now, it looks like this Terk connector may be the way to go but I still have to dig up some more info on that too.