When Gabrielle Lucy Karine Scott (23) started having problems with the 2001 Ford Mondeo she shared with her mum, she quizzed her friends for solutions.
An hour later the quartet had come up with an intricate plan.
One of the group - mother of-three Brooke Ash-Lee Dryden (22) - called her involvement ''the worst decision of my life''.
She and Scott appeared in the Dunedin District Court this week having admitted charges of arson and making a false statement.
Two others were given police diversion.
On October 24, Scott drove to Burger King in South Dunedin, bought some food and parked up, knowing her movements would be captured on CCTV.
Scott contacted one of the others who was co-ordinating the illicit operation, giving them the signal she was in position.
Dryden was dropped off while her friends looked after her child.
As planned, she acted out a kidnapping and robbery, getting into Scott's car and instructing her to drive to a nearby supermarket.
Dryden then took over the driving, leaving her friend to wander to a petrol station where she called police.
Scott claimed she had been robbed at knifepoint and held against her will before the vehicle was stolen.
While this went on, Dryden drove the car to a remote location in North Taieri where she doused it in fuel and set fire to it.
The duo who had co-ordinated the event picked her up but were stopped by police near the scene of the blaze.
They claimed to have seen a ''suspicious vehicle'' further up the road. As they lied to police, Scott maintained the facade.
She relayed her fake experience to an officer at the scene and later, at the station, provided a four-page written statement which she signed as being true.
An insurance claim was made by Scott's parents for the $4000 car but the court heard it was withdrawn before it could be assessed.
Judge Turner noted the pair blamed each other in pre-sentence interviews.
Scott told Probation she had ''snapped in and out of the situation'' and said her mental-health issues may have impacted her behaviour.
Dryden was also assessed as lacking insight into her offending. She displayed a ''belligerent attitude'', the judge said, and claimed it was a spur-of-the-moment decision.
''What actually happened beggars belief. How they could get together and think this was a good idea is beyond comprehension,'' defence counsel Ann Leonard said.
She stressed the planning was minimal but the judge said there was evidence of significant premeditation.
Scott and Dryden were each sentenced to seven and a-half months home detention.
The pair given police diversion ''may consider themselves extremely fortunate'', Judge Turner said.
