Because I often travel interstate and several states do not consider a glove-box as an acceptable secure location for a firearm, I forgo putting any firearm related items in the glove-box. Registration and insurance are clipped to the visor and the wallet with assorted permits and IDs is in the console cup-holder.
The firearms are either on my person, when in Utah: in several easily accessed locations, in a locked case or gun vault when in one of the less friendly states.
I don't declare unless the state that I'm traveling in requires it. In all cases, it's always slow, steady, deliberate movements under the officer's commands. No movement is made towards a firearm unless directed and then I retrieve it "Barney style:"
Officer, I'm reaching for the firearm, as directed, with my right hand.
Officer, I have the firearm in my right hand and I am dropping the magazine [rounds] out, on to the seat (ground).
Officer, I am racking the slide to the rear and locking it in place [opening the action].
Officer, I am placing the safety on.
Officer, I am placing the firearm [wherever directed].
Officer, I am placing my hands back on the wheel.
Unless of course it happens to be one of the OEO from WA, then I'll just let them rant and rave and say nothing.

D. DeWitt - MGySgt USMC (RET)
NRA Endowment Life Member,
Pistol, Rifle, and Shotgun Instructor,
RSO, WSA RSO, Rifle Expert, Pistol Expert,
Utah Concealed Firearm Permit Instructor,
UT CFP, AZ & ID CWP, SAF & JPFO LM, USPSA, IDPA,