Here is what we were discussing ( on calguns.net)when pulled over in California and asked if we had any guns in the vehicle. I know the analogy is not the same but you will get the idea even though police generally ask that question for their and the owner's safety.
"Officer-"Sir, do you have any weapons in the car?"
You-"No Sir."
That would be the quickest and easiest answer to give. It is not illegal to lie to a police officer! If he cannot see any weapons in the car (or things that would lead him to believe there are) and you don't tell him there are weapons in there, he has no right to know about them.
Now, it would probably be a nice gesture to let the officer know if you had weapons in the car, but it's not your job to be nice. No possible good can come of you allowing the law to look at/check your guns out.
Sure, the cop may be a nice guy/gal, and most of them are. But do you know 100% that every gun is being carried completely legally? What if you accidentally left one round in that magazine/cylinder? What if you forgot to lock the box holding your pistol? What if there's a small school a block away you've never seen before and one of your long guns isn't locked up?
There's a million things that can go wrong, and no possible good can come of any of them. (Okay, so you may be able to chat with the officer about guns for a minute, who cares? You're going to the range where there's a bunch of gun guys to chat with!)
You may be one of the camp that says, "I've got nothing to hide, why not let them take a look?" And to that, I refer you back up to the list of questions two paragraphs up. Just because you're a perfectly law abiding citizen doesn't mean you never make mistakes. And one of those mistakes (or something perceived as a mistake by a misinformed officer) could land you in prison.
This all said, the question about weapons is not usually one that an officer asks on a routine traffic stop, so the probability of having it asked is slim, but if it ever comes, it's good to know your rights, and what can come if you choose to waive them.
Remember, that officer can make all the mistakes in the book and be forgiven, you only have to make one to ruin the rest of your life.
You respond "I do not have any illegal weapons in the car".
Here is another one:
If he asks you again if you have weapons in your car, you repeat "I do not have any illegal weapons in the car sir". If he ask to search you car, you say "Sorry, I respectfully decline your request to search my vechicle".
If the officer searches you car and thinks he found something illegal, don't try to reason with him. Shut your mouth and ask him if you are under arrest. If you are, you reserve the right to remain silent. You only have to tell him identification questions like your name and birthdate.