I do think a gun owmer has common sense responsibilities to practice. (Don't leave guns in view in unlocked cars). But, most states by law view a car as an extension of the home, thus an extension of your domain as far as personal protection. If you have a gun locked up in your car, and out of view, and your car is broke into, there is no logical interpretation of law that should hold the gun owner legally accountable. Your domain was invaded and effort had to be made to steal your property (gun).
I've never been hell bent on carrying. Owned a few pistols over the years here and there and never got a carry permit. But, these days we like to travel with it in the boot for obvious reasons, and having a CC makes me legal in almost 40 states to have in my car accross state lines. My step son travels a bit. There's a couple gas stations off the interstate in Macon, GA he would fuel up at on occasion, and said he never stood outside his car at these two places pumping gas without his pistol openly in his hand. Otherwise he said you'd get robbed. (Got my CC approval and all my documents. Just got to get to DMV, pay my fee and get my permit and new DL).