This is a crash course on how not to parent.

Buzzy Netflix documentary “The Crash” follows the twisted saga of Mackenzie “hell on wheels” Shirilla, who drove her Toyota Camry into a brick wall at around 100 miles an hour.

The high-speed accident killed passengers Dominic Russo, 20, and Davion Flanagan, 19, in 2022.

Both men were pronounced dead in the mess of twisted metal, but wannabe TikTok star Shirilla, then 17, was taken to the hospital and made a full recovery.

Investigators found she never attempted to use the brakes, intentionally turning her vehicle into a death trap.

Shirilla claimed she had blacked out because of a medical condition, but she failed to convince a judge. She was convicted of murder and aggravated vehicular homicide and is serving two concurrent terms of 15 years to life.

With two young lives snuffed out, the documentary was both harrowing and heartbreaking. But it was also infuriating.

Because, at its core, “The Crash” is a portrait of horrible parenting. It’s the story of two adults so loath to find any fault in their own child or impose any boundary that they created a defiant Mean Girl on a collision course with trouble.

It’s a shame she took two lives in the process.

Parents Natalie and Steve Shirilla — who, incredibly, is a teacher — were so indulgent and foolish, even my tweenage niece was disgusted by them.

It’s revealed in the doc that the couple allowed their 17-year-old daughter to live with her 20-year-old boyfriend and to smoke weed. And when she was disciplined at school for bullying, her father took her side, denying she was responsible for anything. They barely managed a shred of remorse or humanity at sentencing.

Their style was a noxious mix of lax child-rearing and a strong but deluded belief that the world was as enthralled by their daughter’s bratty attitude as they were. They were not only permissive of her poor behavior, they seemed to revel in it.

We’re first introduced to Shirilla in a montage of seemingly innocent and normal carefree teen moments. There she is in a bikini walking into a body of water, or making kissy faces as she sits in the car with Russo, whom she started dating her freshman year. In an extreme close-up, the pair are on a Ferris wheel looking into their camera instead of out into the world around them.

These now-haunting moments flashed across the screen as an upbeat pop song played.

Steve and Natalie entered the story in bodycam footage from the hospital as the distressed pair try to wade through the post-crash chaos. Then we met Steve again, sitting for his on-camera interview about his daughter’s fatal crash, inappropriately dressed in a T-shirt with the word “Boom” splashed across it.

The word “jackass” came to mind.

The more they spoke, the more they morphed into the parents who wanted to be their kid’s friend. And as footage emerged of their daughter repeatedly smoking bongs, the derelict dad admitted that he knew, adding: “I don’t have a problem with her smoking dope.

“If you’re going to smoke a drug, that’s the one I believe you should take… you know, she’s not shooting up.”

Meanwhile, Shirilla didn’t let her hospitalization from a car crash that killed her boyfriend and friend stop the camera rolling. She posted images from her bed and a video of her mother wheeling her out. Around that time, a clothing company reached out to Shirilla to collaborate, her mother enthusiastically responded, writing: “Thank you for this opportunity. She’s been trying to contact you guys.”

At sentencing, Natalie heartlessly asked the judge for leniency because “this is a tragic accident she doesn’t remember. Davion … he’s a new friend,” she said.

The judge cut her off, demanding: “What does that mean? His life was worthless?”

A frazzled Natalie apologized to the family of the victims — shamed by the judge into a basic act of decency.

They looked so bad in the documentary that after it aired, Steve was put on administrative leave from his teaching position at Mary Queen of Peace School in Ohio.

He whined that the producers didn’t air his full comments. But given what we’ve seen, I’d believe they generously spared him more public humiliation.

Meanwhyile, Shirilla has gained a reputation in prison for flaunting hickeys from her multiple female lovers and happily goes by “Shirilla the killa” according to an ex-lover.

In another ill-advised move, Shirilla sat for an interview, looking detached but maintaining her innocence.

“The Crash” also exposed the vapidity and narcissism of influencer culture.

Like many, Shirilla dreamed of having legions of followers, but what did she have to offer? Great personal style? A skill? Wisdom or ambition? None of the above.

I guess now she has one thing to offer — a cautionary tale.