LOL. Yah, I can always discern my tag numbers, even with my stereo on and the wind blowing in, and even if I can't understand another word. They don't always wait for registration, wants/warrants before the stop here however.
As for concealed carry, notification is required in Utah when "approached" by an LEO. It's probably wise not to mention guns or weapons when doing so. Hands at 10 and 2, "I have a concealed permit... what would you like me to do" will usually prevent you from getting drawn on.
That sounds like a diplomatic way to handle it.
I've had officers ask where the gun is, but never had them order me out of the car or had them even want to see it.