Alright, I found another source of good, credible information that I just tested. I have all of the options now, appearing, but in my tests, I am not receiving the messages...but pretty close. There's a couple of pre-requisites to make it work...foremost is that your iPhone screen must be LOCKED. This makes sense, actually...they don't want a person fiddling with the iPhone, so these features work when you've locked it.
Here's the URL to the source... again, I'm ALMOST
there. Everything seems to be set-up correctly, I get the same menu features (like filters), but the incoming messages do not seem to get into the car's system.