Such a sad video. I am so sorry for that child's death.
I have to be honest though and I hope I say this without mushing it up. The child died because his car's seatbelt failed to keep him and his booster in place. If the seatbelt clasp had worked properly, nothing fatal would have happened and the parents would likely still be happily using booster seats.
IMHO, the battle should be to make booster seats more secure and safer in vehicles. (I don't believe the issue should have been murked up advising another class of car seat types (harnessed) in a 'what-if' scenario) This would have happened to an older child in a booster too.
I truly believe that Booster seats need to be attached with something more than a single point at the seatbelt!
Ever since I began researching the next seat for my daughter last winter, I've looked at the boosters as being stupidly reliant on a single point of securement at the seat belt buckle. That's a lot of faith and trust in a buckle that's designed to open and shut by pressing a button. If there was a lockover panel covering the clasp and preventing access to the button, it would be very helpful, imo.
There's a lot of emphasis on car seat testing on this site. There's another side of the issue. What about testing the various cars' buckle, seatbelt designs, and framework of seating arrangements to safely contain a child seat in the vehicle? This isn't something that is originally thought of by most engineers. Adding a booster seat changes the physics of motion dynamics by adding a framed seat + a child on the seating platform. This Gen 3 seatbelt is a tragic example of design failure. I could see where a regular harnessed or infant seat base could also not work and have deadly outcomes, but at least there's a higher chance of remaining within that vehicle. Having more than a single point of securement helps them. Why should this not be so for our booster seats?
It's the primary reason I purchased the Recaro Start... It was the only booster at the time (and I think it still is) with a top tether hookup! I was concerned with the head/shoulder area of the car seat slamming down against my daughter and the seatbelt in an accident. I was also worried about the single point seatbelt failure and wanted to provide something 'extra' to keep that seat in place. I don't know if these is are unrealistic concerns, but imo, it was something that could possibly occur during a collision. I also wanted to make certain that the carseat would not go anywhere if it was not occupied.
Eventually, our children will leave 5pt harnesses behind at some point in their lives. Boosters are the next step. I'd be thrilled if I had a 4pt option as an adult (no crotch strap & only over the hips & shoulders), but it's not going to happen. We can't get adults to wear 3pt. Why would they even consider a 4pt over the shoulder? Booster seats NEED to become safer by attaching to the car like every other car seat style out there. We have everyone else fastened securely to the vehicles, why are boosters an exception to the rule? I was thrilled to see the backless booster in Canada with a Latch hookup -- Now that's what I"m talking about!
Ok, I'll get off my soapbox now.
tchuss