So it's legal for me as an Elbert County resident to transport my AR through Denver with a 30-round magazine, yet if I lived in the city, I couldn't even possess one? I'm not arguing whether that's correct or not; I'm just astonished at the (il)logic of it. I'm guessing that if they found my AR, they'd try to hassle me, regardless of where I live. Not bashing cops here; hell, my brother is one in COS. I'm just thinking of how it might really play out.

You know that if they have reason to search your car, they're going to look until they find something. I'm guessing that most policemen would rather not get tied up in the paperwork that would go along with that sort of arrest. They're only human, after all. Throw 'em a bone so they won't go any further. (Learned this trick decades ago when Quality Assurance showed up for their inspections.) How about transporting the rifle with a 5-round magazine in it or near it. Stash the others somewhere else in the car, far away from the gun. Maybe they'll see the rifle and legal magazine and let you go on your way.