Travelling down a remote road, Sam Price-Purcell was suddenly grabbed by a man sitting in the back seat.
Michael Jay Evans continued driving as his 25-year-old passenger struggled before being wrestled into the rear of the vehicle by the other man.
Mr Price-Purcell was then taken out of the car and shot by the other man.
Days later, Evans burnt the body.
Mr Price-Purcell's remains have never been found.
Eight years after Mr Price-Purcell was first reported missing, Evans, 41, has indicated he intends to finally reveal the body's location after being sentenced in Brisbane Supreme Court on Friday.
Evans and Mr Price-Purcell knew each other through the criminal underworld but had a falling out over a debt.
Hearing rumours of Mr Price-Purcell making threats, Evans came up with a plan.
The intention was to seriously assault Mr Price-Purcell and that weapons might be used.
In February 2015, Mr Price-Purcell thought he was going to discuss the debt when Evans picked him up with the other man in the vehicle in Brisbane's north.
They were driving toward Toowoomba, west of Brisbane, when the other man leaned forward and put his arm around Mr Price-Purcell's neck with considerable force.
Mr Price-Purcell put up a fight, biting the man, but to no avail.
Evans stopped the car and his "military grade" shotgun was retrieved from the boot.
After Mr Price-Purcell's limp body was taken out of the vehicle, he was shot by the other man.
It is not known whether Mr Price-Purcell died from strangulation or the shotgun blast.
Evans and the other man then rolled Mr Price-Purcell into a tarp and left the body in an embankment.
They went to a property and burnt their clothes before Evans showered.
In the following days Evans returned and burned the body.
"A life has been needlessly lost," Justice Melanie Hindman said.
"To burn the body to avoid detection is really disgusting conduct.
"It has deprived a family of the remains of their child and slowed and frustrated investigations."
At the time Evans appeared shocked and distressed, saying he had shot and strangled "the life out of a (bad person who) deserved it", the court heard.
He later claimed he was suffering from recurring nightmares and that the "smell of burning flesh would not go away".
Evans also told people he and another person had hurt someone and it had "gone too far", court was told.
A month later Mr Price-Purcell was reported missing by his mother.
"We will never get to hold him, celebrate him, enjoy his wonderful sense of humour and loving warmth again," she said in a victim impact statement.
"Now my only hope is that Sam's remains will be returned to us so that we can lay him to rest under our terms."
Evans - who has been in custody since June 2018 - has expressed an intention to disclose the body's location following his sentencing.
His defence barrister later added: "He will not get parole if he does not co-operate".
Evans was initially charged with murder.
He was sentenced to 10-and-a-half years in jail on Friday after pleading guilty to manslaughter and interfering with a corpse.
Evans must serve 80 per cent of his sentence before he is eligible for parole.
