The pair entered not guilty pleas but were found guilty on May 27 this year.
The court heard today Ali was still working for Park n' Fly and studying to be a teacher while Mabshar was working for a hotel as a porter, including driving a shuttle service, and studying computer science at university.
Both men - who defended themselves in court - argued that a conviction would make them lose their jobs, hinder their future careers and affect their families.
"I'm only 19 and I've just recently started university a year ago," Mabshar said. "It would affect my studies [and] I've also taken out a student loan, quite a large student loan ... it would be very, very hard for me to pay."
Ali agreed: "I'm a university student going to be a teacher. It would really affect my degree and future employment. Teachers with convictions are put down on the list."
But Judge Greg Hikaka was not convinced there was a "real risk" a sentence would have an impact on their futures and said it was important for community protection.
"The offending has been escalated by the fact that they were using other people's motor vehicles in the course of employment that required those motor vehicles to be moved from one location to another... so there is an abuse of trust, and that needs to be recognised.
"The public entrusting their vehicles to those who provide the sort of service that the defendants were engaged in means that the public won't be able to necessarily have the level of trust that they should have in that business."
Police prosecutor Jay Choi opposed the men's application for discharge without conviction, stating the offence deserved a moderate sentence.
"It's not a minor offending," she said. "Discharge without convictions shouldn't be granted in this case."
Ali was dealt a six-month driving disqualification and 40 hours of community service due to previous driving convictions, while Mabshar received the minimum three-month driving disqualification.
The maximum penalty for the charge is three months imprisonment.
The Herald previously reported that a Tauranga customer, who asked not to be named, was the man whose car was impounded in 2014, shortly after he left the country for an Australian holiday.
"We dropped the car off at about 11 o'clock and they took us to the airport. That part was fine. Then we went to Australia and came back a couple of weeks later and ... they seemed to have trouble finding the keys."
He said a manager arrived and told him the car had been seized, and Park n' Fly paid the fees and arranged to have it sent back to him.
A spate of complaints from aggrieved Park n' Fly customers emerged in January this year, after the impounded car case was revealed.
Neill Ellis, who left his car with Park n' Fly in Auckland while on a trip to Melbourne in 2014, posted a video on Facebook from his dash-cam showing the driver revving the engine and tooting.
Park n' Fly told the Herald in January the driver was no longer with the company.
Other irritated customers told the Herald in January their cars had been returned with dents and coins or petrol missing from their vehicles in the past.
The company said at the time drivers who left cars with Park n' Fly were often in a rush and didn't always thoroughly check their cars before jetting off. Some had no idea how much petrol they had.