Cars are not guns. Cars are useful tools with a purpose other than killing people. People need cars to get around. And no one uses a car to deliberately kill children.
Guns have no other purpose but to kill people. And very few of us have need of them as a tool. And because they make killing people so fast and easy, we really need to be very careful who we allow to have them, and why.
But this is just common sense. Which has been soundly rejected by the political and religious right. Because the gun manufacturers have been tickling their fear and ego for so long that they now think they all have to have piles of guns. And that there should be no laws regulating the ownership or use of these guns.
To see just how insane this really is, imagine a world full of automobiles, that anyone could buy and drive away in for just a few dollars. And society having no traffic laws, or signs, or stoplights, or anything at all regulating who's driving where, or how.