I am curious why OnStar doesn't allow you to store contacts in the vehicle phone book like before?? I can't remember all my phone numbers I have in my phone. If I lose my phone I need to use my car phone to call someone! I need to store names and numbers of my family and children.

Yeah, the manual doesn't show a way to do that with the OnStar. I don't personally know why. How many model years ago was "before" when they used to store contacts onboard?

As for a solution, it might be a good idea to put important phone numbers on a small piece of paper in your wallet. This will help you in the car and other places as well.