Ben Platt struck in Hilton Street, Dunstall Hill as Saman Thanthirige Don was helping two customers collect their shopping from the boot of his Vauxhall Zafira after driving them home from a supermarket.
The 26-year-old, who just happened to be passing when the taxi stopped in the street, pulled out a knife and threatened to stab the driver who was cut during the struggle that followed, Wolverhampton Crown Court heard.
Mr Thanthirige Don, who feared for his life during the clash, was left in the road as the defendant jumped into the Zafira and drove off towards Wednesfield Road but had not got far when he crashed into three parked cars at speed on purpose, writing off the taxi, said Miss Alex Kettle-Williams, prosecuting.
He grabbed £70 worth of takings from the wrecked vehicle and ran off despite being injured in the smash. The defendant was identified through a DNA match with blood found on an air bag in the car.
Mr Jon Roe, defending, said Platt suffered from attention deficit hyperactivity disorder, epilepsy and learning difficulties.
The lawyer continued: "He committed these offences when his mental health was at a low point. He had separated from his partner in difficult circumstances and was drinking heavily. He deliberately crashed the car to harm himself."
Plant, who lives in Burton Crescent close to where the attack happened on March 22 2017, pleaded guilty to robbery and criminal damage but denied threatening the driver with a bladed article. He was convicted of that offence after a trial.
Judge Michael Challinor said as he sentenced him: "The jury dismissed your claim that you wanted the car to commit suicide.
"You attacked and threatened Mr Thanthirige Don with a knife and tried to stab him. He defended himself and suffered cuts and injuries during the altercation during which he feared for his life.Then you took his car and wrote it off by crashing into other vehicles.
"He has given up being a taxi driver for fear of being attacked again. He has lost his lively hood and the attack has changed his life. Whether it will continue to echo down through the years is another matter."