After digging through the rule the NHTSA adopted, there’s nothing in there that mandates side glazed windows. The rule covers ejection mitigation. The summary hits the major point:

The agency anticipates that manufacturers will meet the standard by modifying existing side impact air bag curtains, and possibly supplementing them with advanced glazing. The curtains will be made larger so that they cover more of the window opening, made more robust to remain inflated longer, and made to deploy in both side impacts and in rollovers. In addition, after deployment the curtains will be tethered near the base of the vehicle’s pillars or otherwise designed to keep the impactor within the boundaries established by the performance test. This final rule adopts a phase-in of the new requirements, starting September 1, 2013.

There’s a lot of discussion in there. The document is over 300 pages. Some of it covers how the side windows can be down or could become deformed from a roll-over. For testing procedures the windows have to be pre-cracked or removed.

The Federal Registrar calls out side glazed windows in 49 CFR 571.226:

S1. Purpose and Scope. This standard establishes requirements for ejection mitigation systems to reduce the likelihood of complete and partial ejections of vehicle occupants through side windows during rollovers or side impact events.

and in 49 CFR 571.226 S4.2.1.1:

S4.2.1.1 No vehicle shall use movable glazing as the sole means of meeting the displacement limit of S4.2.1.

I anticipate that mid to higher end vehicles will have side glazed windows. While lower end vehicles will not.

Apparently it was because people’s arms (or even heads?) would hang out of the broken window when a car is rolling over at highway speeds.

Makes me think of the supposed bullet-proof cyber truck glass… Odds are much more likely you’ll be trying to escape your car than be under a hail of gunfire lol.

I’ve just learned that laminated glass is now mandatory across all models since 2020.

https://lifelinerescuetools.com/blog/3397/

This is apparently a common thing across car manufacturers now.

death by own car is probably the pinnacle of poor UX.

But everyone that gets in my car for the first time manages to find it if I forget to tell them to press the button with the minus sign.

Yeah, but it’s way harder under water.

I punched a window and broke it back in the day, but that was a junk car from the 80s we were destroying. And I was outside of it with all the room in the world.

Trying to do it while seated inside would have been impossible, and underwater all that pressure against the other side spread out equally makes it really umpossible. It’s basically a giant cushion that absorbs and distributes the force. If you do break it, all that water pressure is going to push it straight in your face, and chances are you’re just going to let the water in, but not create a whole big enough to climb thru. Certainly not u til your car is full of water and pressure equalizes.

If you’re worried about this enough to carry a glass breaker, take a page from the Kia boys and make sure it’s ceramic. Even steel with a point is going to be difficult. But ceramic will shatter it with almost no effort. Gotta keep on bipping