For me, the best truck gun is the one that goes with me when I get out of the truck (currently a Shield 9mm). I've had my truck stolen before and I just can't stomach the idea of one of my guns getting into the wrong hands because it was stolen again (BTW: for a few years, a 2004 Dodge Ram Quad Cab was the 2nd most stolen vehicle in the country). I'm not saying no one should ever leave their guns in their vehicles, I just know that I can't do it.