Why would the police be looking in your trunk in the first place? they either need your permission, a warrant or reasonable suspicion that you are doing something illegal to look in your trunk. Let me quote a friend who is a long time cop, "Regardless of how nice the police officer might seem, and the fact that you are doing nothing wrong, you never ever let an officer search your home of vehicle without a court order". There are to many activist, sociology degree'd, social engineering douche bags in uniform these days.
And never volunteer information to the officer that you have a gun in your car unless they are legally about to search it.