I got my 2010 Nox in November 2011. I tried on 2 seperate occasions (months apart) to get the trial and both times it failed. Stopped trying. You are correct, how often do you need it.
The primary reason to contact OnStar was that every time I use the bluetooth function it answers me in French (my truck was originally purchased in Quebec). The truck has no way of changing it. I contacted GM-online and they told me OnStar controls that.
I have no real problem it being in French (since I undertsnd it) now that I saw what a pain in the
it is cause I know if I call again I will be harased all kinds.