A driver phoned emergency services as his car sped down a motorway at 119mph (192km/h) after the cruise control locked, an inquest heard.
Kaushal Gandhi, 32, of Harrow, Middlesex, desperately tried to stop the out-of-control Skoda Octavia before it crashed into a parked lorry, killing him instantly.
In the eight minutes leading up to the collision, Gandhi told the call handler that the cruise control had become stuck and he could not stop the car accelerating.
A recording of the panicked phone call was played to a coroner in Beaconsfield, Buckinghamshire, today.
The inquest heard company director Gandhi, described as a "meticulous" driver, speaking to the Thames Valley Police call handler as he passed Junction 2 of the M40.
He said: "My car is not coming out of cruise control. It is not letting me stop. It [the speedometer] shows 70mph but I think I am going much faster than this."
The call handler replied: "Can you try to control the car's speed using your gears?"
Gandhi said: "I am trying. It is not stopping at neutral."
He tried to turn off the engine by pressing the start-stop button before continuing: "I have kept pressing the button but all it makes is a noise, my speed is increasing.
"I think what has happened was I tried to change the mode on the car, because I was on the sports mode. I pressed a button to come onto the normal mode and then it is not allowing me to do anything."
Gandhi later said his speed had "just gone 77mph" before the call handler asked if he had tried using the handbrake.
The driver said: "I haven't tried it because at this speed I am not sure what will happen. I am in the middle lane right now, there is no traffic. Do you want me to try the hand brake?"
The call handler, who was then seeking advice from a colleague, got no response to a question and the crash then happened.
The coroner heard that the phone connection was lost moments after Gandhi was heard saying: "I am just going to check that, one second ... "
The call handler was then heard saying: "Are you still there? Hello, operator, I've lost the line."
The Skoda crashed into a lorry parked in a lay-by after the M40 merged into the A40 shortly after 3am on February 2.
Witness Robert Hague, who phoned emergency services, told the inquest the car was "almost completely embedded in the lorry" and the roof was "peeled back".
Lorry driver Emma Parrot told the inquest she was thrown from her bunk with the force of the impact, adding: "I realised immediately that anyone in the white car was unlikely to have survived."
Martin Clatworthy, a vehicle data examiner and safety safety specialist for Volkswagen, the makers of Skoda, told the inquest that in the five seconds before the crash, the vehicle was travelling at 116mph (187km/h) and the accelerator pedal was fully depressed. He added there was no braking recorded.
Clatworthy said: "There is no indication that there was any error or problem with any of the electronic systems of the car in the five seconds leading up to the collision."
Police collision investigator Andrew Evans said the faults Gandhi described would have meant the Skoda suffered a simultaneous mechanical and electronic failure.
He explained that applying the handbrake could have saved Gandhi's life by forcing the car's rear wheels to lock up and turn it around so it skidded backwards.
Family friend Gatinder Kaur said Gandhi had been "like a son" and a "close and trusted friend".
Kaur said Gandhi, who was born in Mumbai, India, had many interests including archery and sky diving. He had also recently reconnected with an ex-girlfriend in India after his marriage ended in February 2015.
Kaur said the breakdown of the relationship did not "cause him any concerns", adding: "He was on top of the world, he had everything to live for."
The coroner said a post-mortem examination at the John Radcliffe Hospital in Oxford gave the cause of death as multiple injuries. A toxicology report showed no substances in his blood that would affect Gandhi's driving at the time.
Senior coroner Cripsin Butler said that data analysis from the mangled car's airbag systems failed to provide evidence of the defects Gandhi was describing to the call handlers. He recorded a narrative verdict.
THE DESPERATE 999 CALL
"My car is not coming out of the cruise control.
"I have just passed the exit of the M40 towards Slough. It is not letting me stop. It (the speedometer) shows 70mph but I think I am going much faster than this."
Call handler (CH): "Can you slow to a stop by braking? Can you try to control the car's speed using your gears?"
KG: "I am trying. It is not stopping at neutral.
"I have kept pressing the button but all it makes is a noise.
"My speed is increasing. I think what has happened was I tried to change the mode on the car, because I was on the sports mode. I pressed a button to come onto the normal mode and then it is not allowing me to do anything."
"It is just gone 77mph right now."
The call taker was then heard asking if he had tried pulling on the handbrake.
KG: "I haven't tried it because at this speed I am not sure what will happen. I am in the middle lane right now, there is no traffic. Do you want me to try the hand brake?"
The coroner heard that the phone connection was lost moments after Mr Gandhi was heard saying: 'I am just going to check that, one second... '
CH: "Are you still there? Hello, operator, I've lost the line."
HOW THE OCTAVIA IS TOP OF THE LEAGUE FOR SAFETY
The Skoda Octavia is known for being one of the safest and most reliable cars on the market in Britain.
It was rated the best family car in the WhatCar? Car of the Year 2016 awards, with the judges praising it for having the 'latest safety equipment' and the power of a "small but mighty engine".
It has been praised for having seven airbags - including a driver's knee 'bag - and a post-collision braking system, which has helped it receive a safety rating of five stars from Euro NCAP.
The car has a top speed of 122mph and can do 0-62mph in 10.2 seconds.
It is one of many vehicles available on the market with cruise control, a function which maintains a car's speed by taking control of the accelerator.
It can help make longer journeys more comfortable and help drivers maintain their speed and avoid speeding fines.
Most vehicles with cruise control have a system whereby the driver must climb to a certain speed and then press a button which will maintain this speed.
It can be turned off by applying the brake or the clutch in a manual car.