The lady who taught my HCP class told us that... You are not required by law to inform the officer you have a HCP, or that you are carrying. BUT... she, and the deputy for the local Sherriff's department who was in the class (his wife was taking the class), said that she advises, and the deputy agreed....
If you are pulled over, put your hands on the steering wheel, and advise the officer that you are "LEGALLY ARMED". Don't just stick your head out the window and yell "I HAVE A GUN". Then wait on the officer to reply, and follow what ever instructions he gives you.
The Sherriff's Deputy agreed, and said that was the best way to hanle it, and most time during stops like this, if there was not a major infraction, he THANKED the people and told them to have a good evening.
Also, if I'm not mistaken, you can now carry a loaded firearm in your car even it you don't have a HCP. Just don't get out of the car with it.