This morning (Dec 6), North Yorkshire Police confirmed the driver of the car, a 20-year-old man, later died in hospital.
A statement from the force said: "The 18-year old front seat passenger of the car was pronounced dead at the scene. The 20-year-old driver was taken to hospital with serious injuries. Sadly, the driver later died in hospital.
"Our thoughts are with the families of both males, they are currently being supported by specialist officers."
North Yorkshire Police's major collision investigation unit are now appealing for anyone who may have seen the car to contact them. They are particuarly keen to hear from anyone who was travelling along the B6480 towards Settle at approximately 9pm and has dashcam footage.
Contact police on 101, and ask for PC Drake, or email [email protected] quoting incident number 12210254436.