Tangent to the article: I have often wondered if it would be advantageous to start offering an optional 2nd sash belt to better secure the passenger to lateral movement, and spread the belt load across more area.
I like the idea of some sort of head restraint. The challenge with a head restraint would be making something not restrictive, and silly looking, otherwise people would just not use it.
We could make cars significantly more "death-proof" with rollcages, harnesses, helmets, speed-limitors etc. But we don't, and for many good reasons.
My (somewhat drawnout) point is that design of these features matters not just from a safety result pov.