Gilfo;
I'm in what I call "Outer Montana". In other words, high-people-density is more than a few miles away. Even then, Montana's H-P-D as a whole doesn't even register a blip in coastal states. With that being said, my leave it in the truck gun is a small .22 rimfire rifle. It's compact, fits under the seat, and is purely a just in case firearm that I'm comfortable with. We know, for an absolute fact, that both bear and mountain lion travel through our property.
Here's some of my reasons for going the way I did. 1. I literally live in the middle of a Minuteman missile field - if the balloon goes up, suvivability just isn't there, I can't dig deep enough. 2. I always lock the vehicle. 3. I'm always armed with a major caliber pistol. And 4, if there's any perceived need for heavier firearms, they're in the truck on a temporary basis, rather than a permanent one. That's also very easy for me to do.
900F