I would never want to allow for a situation where the officer would discover I'm carrying by surprise, of course, but if I'm carrying IWB and hand my documentation over when they arrive at the window that's not going to happen. Now if they want me to get out of the car, I'll let them know.
The one time I did inform (required by law in that state) the officer at first refused to give me my ammo back and said he was afraid I'd reload and shoot him before he could leave...this in a situation where I'd called them as the victim of a crime. A couple times during the encounter he was so jittery I was afraid he was going to draw on me. It was a very stressful experience.
In other threads like this people have shared experiences where a well-intentioned FYI to an officer turned into staring down the barrel of a service pistol...one LEO said if someone was kind enough to inform him he'd "tell them not to do anything stupid or he'd shoot them in the f$%king face". How professional, really encourages voluntary cooperation.
I'm glad people here have had good experiences and the LEO who have chimed in seem reasonable. But in LEO like any other profession, there are good apples and bad ones. I have nothing to gain by informing in a situation where the LEO would not discover the firearm, but significant risk if they are the bad type. I'll pay the extra ticket cost, if that's all it will save me.
I obey laws so I've only been pulled over a couple times...last time I was carrying IWB with my wife and two kids in the car. I had no legal obligation to inform, and nothing to gain if some jumpy officer was going to point a weapon at my family. I did not inform, I was polite and cooperative and had my documents ready when they got to my car, got a warning, and went on my way.
Wow! What I would have done is ask for a supervisor to visit the scene and followed through with a statement or whatever the supervisor said do. I stopped a fellow about 2 am for speeding who was all jumpy and nervous and when I asked if he had any guns, knives etc he got freaky. Turns out he had a loaded .45 under the front seat. After checking to make sure gun was not stolen and hearing why he had it there (he wasn't carrying to go armed he was returning from his farm where they had been shooting) I unloaded it put rounds in the bed of his truck, uncuffed him and sent him on the way with a speeding ticket- Oh yeah, told him if he wanted to ride around with a loaded gun to either get a job in LE or get a carry permit. Not everyone with a gun is a bad person, lot more good folks out there than bad we just hear about the bad all the time.