There have been a few too many "gun stolen from car" threads lately. Only one that I recall had a semi-happy ending, and that one was returned (well over two years after recovery, and with maximum resistance from the DA).
Where do bad guys get guns? Do some reading, and you will find that they purchase them through "legal" channels (straw purchase) once in a while. The remainder of the time they steal them or buy from someone who has stolen them.
If each of us worked a bit harder to keep our own guns out of the hands of bad guys, I believe the results would be dramatic.
Too many gun owners believe it is their "right" to store their gun(s) irresponsibly and bitch and moan when some thief acts like a thief.
And so it is...for now, but there are plenty of folks who would love to pass legislation restricting your (and my) RKBA.
Worry less about the ammo cooking off, and think about the repercussions of storing an unlocked, loaded firearm in yout glove box all day, every day, or worse yet, all night, every night...