They call it the "Newman Bar". After his bad wreck in 2003, he lobbied NASCAR to add an extra bar over the top of the roll cage to protect the driver. NASCAR did it and that probably saved his life. At least that's what I read.

so
how come passenger cars are not this safe?

The changes that NASCAR made over the years since Dale Sr.s wreak has saved a lot of drivers.
That wall absorbing the impact did what it was designed to do, and his car hitting that wall reminded me of when Dale Sr. hit the wall almost exactly the same way.
You could see the wall give from the impact, but when he flipped and the other car T boned him on the drivers side I knew that wasn't going to be good.

I've often thought this myself.
Those cages are made to protect the driver doing 200 mph, so why can't cars be built with a cage that can protect from say 100 mph?
Yeah, I know, weight, yada, yada, yada!

Several factors. The biggest one is price of course. The technology is out there, but its not cheap. People would flip their sh** and cars would be affordable to the masses if we made them as safe as we possibly could... its a known compromise.

Another big one is convinces. What are we willing to put up with? We know, beyond any doubt, that four point seat belts are much better at keeping a passenger or driver from moving in an impact. But who wants to be bothered with a cumbersome process such as strapping one of those on and making sure its properly adjusted for each occupant? Its a hassle.

Look at racing seats. They are not meant to be comfortable. They are designed to be safe. They cradle the head and neck area and flare out to protect the drivers mid section. Big time racers like NASCAR have them custom made to fit the drivers body like a glove. That would add tremendous cost to a car, not to mention who would want to sit in an uncomfortable arse seat?

Making passenger cars safer will only go so far, its the drivers that are the problem. Outlaw cell phone use and implement tech that makes sure you cannot use cell phones when driving...that would cut auto deaths in half right there.

That's good news. Just saw were him and his wife are getting a divorce 5 days before the big wreck.

If you look at today's passenger cars, versus cars from the 80's it's night and day. I became a volunteer fireman in 1982 and finally gave it up in around 2007. The mid eighties were carnage, until airbags showed up. I remember he first head on collision I saw with an air bag equipped car. I was thinking double fatality. I was wrong, the guy in the pick up died, the guy in the Chrysler Lebaron with an airbag walked away. The old timers on the fire department swore that "back in the day" when they used to be able to do extrication with a Saws All and Porta-power because cars just didn't crumple they were safer. Us kids with our Jaws of Life, didn't understand simple physics. In reality the physics were newer cars crumpled to absorb energy and protect passengers.

There's a Chevy video on Youtube of a head on, offset collision between a 1960 Chevy Bellaire and a late model Impala. The Bellaire barely crumpled and the crash test dummy sustained fatal g-forces and impacts. The Impala looked like it had already been through a car crusher and the dummy suffered minor injuries.