The car was the first of its kind in the country, and so was being fixed with a kit the company had imported from the US.
Timmerman said Mosley texted him about the parts arriving on July 25 and he started working on it at the start of August.
The self-proclaimed "petrolhead" said he was pretty excited.
"Every time a project like that comes in everyone gets excited; it's our passion."
Timmerman said he was fairly used to working with high-end cars, but this vehicle was at the top end of this scale.
He and his team at Power Torque fast-tracked the work and Mosley picked up the modified car up from the garage several weeks later.
He initially seemed happy with the work, Timmerman said, which was of an "extremely high" quality. But soon after this Mosley discovered several issues with the modifications as well as the process undertaken by Timmerman's team.
Mosley told the Herald he assumed the company would run his luxury car on a dyno machine as part of the tuning process, as well as running it briefly on the road.
"But when I picked the car up from them it had another 600km on the speedo than it did when I dropped it off", he said.
He said he also discovered it had been driven at speeds of up to 170km/h.
Unbeknown to the team at Power Torque, Mosley said he had an aftermarket GPS system, which showed him the car had been driven to Rotorua and back - twice.
"It looks like they took it for a joyride, obviously because they liked the car."
"I shipped the car on a truck to them [from Auckland] so it didn't have to be driven from all that way", Mosley said.
Mosley wasn't sold on the company's claim that most of the added mileage was done on the dyno machine. He said his suspicions were confirmed when weeks later he noticed a picture of his Lamborghini down a side street in Rotorua.
He was fuming.
Timmerman said things started getting nasty after he drove up to Auckland on October 5 to sort out the issues his customer wanted fixed and to sort out some paperwork.
But when he arrived in the city, the car owner said he was too busy. Timmerman was peeved.
According to the mechanic, it was week after this that the excuses, the abusiveness and the text messages started rolling in.
He's employed the services of a lawyer, who had sent a letter to Mosley demanding payment of an outstanding $58,000 and threatening defamation action for the Facebook posts.
The letter also said Timmerman was calculating the damage suffered, which was expected to be "significant".
Mosley said he'd spoken to the Motor Trade Association about the incident, but had all but given up on the company rectifying the situation.
"The damage has been done."
The Aucklander, who said he had turned his life around since serving four years in prison for dealing class A drugs and carrying a pistol, said he had planned to on-sell the car. It had already been listed for sale on Trade Me.
Consumer New Zealand adviser Maggie Edwards said that under the Consumer Guarantees Act a garage had to take reasonable care and skill while doing its job.
