Chelsea Klein, 29, was in the back seat of the vehicle stopped on New York City's West Side Highway when a woman forced her head inside the car and began yelling at the Lyft driver, several media outlets reported.
Klein -- who wasn't immediately available to speak when Daily Voice reached out Thursday afternoon -- got it all on camera.
"She thinks it's cute that her driver almost hit my kids, and she thinks she needs to take a video of it," the woman dubbed "Kidz Bop Karen" said into Klein's cell phone.
Klein gave "Karen" a thumbs up when she saw her flipping off the Lyft driver. When both cars came to a stop at a red light, "Karen" got out and stuck her head inside of Klein's Lyft.
"Do you think stopping int he middle of the road is going to help?" Klein asked the enraged woman.
"You being a bi**h is going to help," she responded.
Klein reminded the woman that her kids, still in her vehicle, might hear, to which the mom responded:
"They can't hear me because they're listening to Kidz Bop."
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