Now that we've established that, here is my current fleet of commuters:
2004 Corolla with 240k miles
2005 Matrix with 165k miles
As a fellow parent who's also very interested in safety (we've never bought a car without me first looking intensively at the safety data of the ones we were considering, and we've always chosen the one with the best safety data), here's my advice. Two things:
(1)
Get a car that has dynamic stability control, a.k.a. electronic stability control. In other words, if your cars don't have it, trade them in for one that does (or if you really need two cars, two that do). DSC/ESC became mandatory on all cars sold in the US as of 2012, but it was available on Subaru Outbacks and possibly other Subarus at least as early as 2007, at least one Toyota SUV around 2005, and years before that (late 1990s) on, I believe, some Mercedes and BMW models. In other words you can find affordable used cars with this feature. Here's why you want electronic stability control:
"The IIHS study concluded that ESC reduces the likelihood of all fatal crashes by 43%, fatal single-vehicle crashes by 56%, and fatal single-vehicle rollovers by 77–80%."
https://en.m.wikipedia.org/wiki/Electronic_stability_control (look at the "Effectiveness" section).
Not to mince words, but HOLY SHIT, that is a HUGE HUGE safety increase. The reason it became mandatory in 2012 was because that level of safety increase was expected to decrease car-crash deaths by THOUSANDS of people per year. And in the US about 30,000 people a year die in car crashes, so we're talking a very significant decrease. One estimate I saw was that once ESC reaches a certain level of market penetration--i.e., it's not on all cars that are on the roads, but it is on a majority of them--we would be seeing about 10,000 fewer deaths a year!
And that's just the deaths--a lot MORE people are severely injured, sometimes permanently disabled, by car accidents. And a safety increase that reduces the death risk
by reducing the number of accidents that happen in the first place is also going to significantly reduce such injuries.
And (2),
get the best car seat you can: best safety and best fit for your kid. It can be hard to find data distinguishing one car seat from another, and all new car seats sold in the US meet the minimum standards. I spent many many hours researching and the ones that had the best stats were the Diono Radian and Clek Fllo (also Clek Foonf but that seat is huge, too big for our car). There was also an amazing Britax, I think--the Advocate, maybe it was called?--but right when we were buying them, they had a recall and weren't available anymore.
Our kids are on the tall and skinny side; different seats with similar safety stats may work better for you if your kid is built differently--our options were narrowed by my desire to keep them rear-facing as long as humanly possible (I had to look at CDC stats on percentiles of height/weight to guesstimate how big they would be at X age--my kids will probably reach the height limit for many seats long before they reach the weight limit--and then look at seats that were on the taller side to ensure that my kids would probably still fit in them rear-facing at, say, age 4). We also wanted to leave open the possibility of having a third child without needing a new car, so there were some wider seats I didn't look at because they wouldn't fit three across. I mention all this just to clarify that the universe of car seats I was comparing for their relative safety wasn't the entire universe of all car seats, but just the ones that seemed best for tall kids and possibly fitting three across our back seat.
Of those two suggestions,
#1 is by far the most important because something that reduces your risk of even having an accident in the first place by such a significant margin is going to do a lot more for your entire family's safety than something that protects your child in a crash.