My policy is to judge each situation on it's own merit. I don't believe it's prudent to arbitrarily inform in every situation. Likewise, there are times when informing the officer could be the prudent thing to do.
In any stop where, in my judgment, I don't believe I will be asked to step out of the vehicle, I don't really see much sense in injecting a firearm into the issue and (perhaps) providing the officer with an opening to feed his ego (if he has one) and "assert his authority" over me, the "lowly" citizen. On the other hand, if I believe the stop is going to involve removal from the vehicle and possibly a pat down, I will likely inform in advance of that action to (hopefully) avoid having some cop point his Glock at me on the side of the road when he "discovers" the gun that, in his view, I was "hiding".
While the vast majority of Police Officer's I know, have met, and have dealt with over the years are good, honest, and professional people, not all of them are. Like any other group of people, there are some losers in the group that, despite the correct legal process for handling a situation, will make it up as they go and follow their own, made-up process for handling a stop. Fighting with one of these clowns on the side of the road, no matter how wrong he/she is, is the wrong thing to do. A little common sense goes a long way when faced with a traffic stop while you are armed.
For the record, we have no duty to inform in my state. Obviously, in any state where you are required to inform, you SHOULD inform, always, and in the same manner as Mr. Ayoob suggests in the video.