If I lived out in the country, it would be a different story. Out in the boonies, you see a lot of left of center accidents, rollovers, and just plain bizarre stuff that you ask how in the world did that happen?, but where I live, in a large metropolitan area, rear-enders are most common, with intersection crashes behind it because everyone where I live runs red lights for about 5 seconds after it turns red. Folks always balk when they hear me say this, but it is true: a majority of accidents can be avoided, even by the people who are not at fault. For instance, I went skiing a couple days ago, had a long drive home on the interstate. This guy passes me in a gray Chevy Avalanche with no light on, and it is almost completely dark. I turn my headlights completely off, and then back on, several times. He doesn't get the message. The person in front of me does the same to him, and the guy never turns his headlights on. This is the kind of driver that could have a freight train headed right for him, and he would never see it coming. i.e. he could have a tractor trailer barreling down on him at a red light from behind, and he would never know it until he was creamed from behind. You have to be pro-active as a driver. I was rear-ended about 10 years ago. As a licensed pilot, I am used to performing scans: left, straight, right, instruments, mirrors, etc, constantly using my peripheral vision. So when I saw this lady barreling down on me from behind, I pushed the clutch in, let off the brakes (as no one was coming from the right or left) and she nailed me from behind pushed me into the intersection, hardly any damage to my old Jetta, and the entire front end of her Kia Sportage was demolished.
Had I not been scanning my surroundings, and had my foot planted on the brake, my car would have been totaled from behind.
Similarly, at intersections, I never go through an intersection without clearing it visually first.
However, a majority of drivers will never do this, never use peripheral vision, and have no idea about their surroundings.
NHTSA stats in my opinion, apply more to "average" drivers.
I can't tell you the number of recorded loss statements I took back in the day as a generalist insurance adjuster, where I would determine fault, look at cars, and other stuff.
So many of these statements I would ask, "did you see the other vehicle before the impact?" and almost every time the person would say "no."
This is very, very alarming to me and just does not make sense. Fact of the matter is, most people driving around are completely unaware of their surroundings.
So regarding my thoughts on carseats, If someone is gonna slam into me, its most likely going to happen from the rear, based on where I live, and based on my habits.
P.S. I have a large road near my place with 5 lanes on each side, and person after person after person will try to make a left hand turn across all 10 lanes to try to turn into the farthest lanes, and they will try to rely on people waving them through (a.k.a. wave of death) or they just don't care. They are so lazy that they can't drive 100 feet up the road so that they can turn at a controlled intersection (traffic light). This is your common driver here. There are so many accidents here with that exact scenario. I would never think about doing this, not only do I park at the back of the parking lot, but I take the time to drive 100 feet up the road so I can turn left at a controlled intersection instead of turning across 10 lanes. Similarly, most of the time, you can see the fool trying to make it across and stop in time, but alot of these drivers, again, they are not aware of their surroundings, and they never see the car turing left, and whammo.