One of the men also used union funds to pay for a dinner worth almost $500 at one of Perth's most exclusive restaurants, and grand final tickets for his wife and mates.
The Royal Commission into Trade Union Governance and Corruption in 2015 found James McGiveron and Richard Burton, both former branch secretaries of the WA Transport Workers' Union, had benefited themselves at the cost of their union.
The report found the duo engineered a situation where they both received a luxury vehicle for personal use, and one a generous severance payout after agreeing to step down from the top job, and take a policy role he knew would be shortly made redundant.
On Friday, the Federal Court ordered Mr McGiveron pay $11,000 and Mr Burton $27,300 for repeated breaches of the Fair Work (Registered Organisations) Act.
According to orders made by Justice Michael Barker, In 2012, James McGiveron, then branch secretary, authorised the purchase of two F350 Ford pickup trucks costing $137,000 each, for Mr Burton and himself.
He did not have authority to authorise such a purchase, and admitted to the Fair Work Tribunal last year he knew he would likely receive one of the vehicles for personal use.
Mr Burton then authorised the purchase of add-ons for the two vehicles which brought their cost up to more than $300,000 total. The union's branch committee which acted in an oversight role was not notified of the purchase.
Fateful meeting set misconduct in motion
In July that year, at a meeting of the branch committee, Mr McGiveron helped change the union's redundancy provisions, which ultimately saw him receive tens of thousands of dollars extra in his severance payment.
Some months after the meeting he resigned as branch secretary and took up a policy advisor role, which was made redundant three months later.
He also received the car as part of his severance package, but has since returned it to the union.
McGivern's total severance package was $477,000, of which $348,000 was his redundancy payout, which was authorised by Mr Burton, who took over from him as branch secretary.
Justice Barker, when delivering his orders, noted Mr McGivern held a significant position of trust.
"The actions of Mr McGiveron bespeak of a high degree of entitlement to act in the way that he did," Justice Barker said.
Lavish dinner and grand final tickets
During his time in office, Mr Burton also used a union credit card to pay for a lavish dinner at Perth's high-end Rockpool restaurant at a cost of almost $500.
He also spent $1,634 for himself, his wife and 10 mates to attend the 2013 September grand final, which he charged to the union, and hired a vehicle to transport personal items to Shark Bay.
According to the orders, Mr Burton said he made out a check for $5,070.39 in April 2014, and sent it to the union suggesting this covered the cost of the dinner, tickets and other personal expenditure.
However, the union's general manager said no such letter was received, and instead Mr Burton tried to hand her an envelope, which she directed him to send to the union's committee.
Mr Burton also said he tried to recompense the cost of the luxury vehicle purchased in 2012, but the money was returned to him.
In his orders, Federal Court judge Michael Barker ruled both bosses had failed to act in good faith for the best interests of the organisation, and with due care and diligence as office holders.
In addition, Mr Burton was found to have improperly used his position to gain advantage for himself.
The two have 74 days to make the payment.
The TWU declined to answer questions from the ABC about the case, but issued a statement, saying their own systems had uncovered the breach.
We referred it to a retired independent judicial officer," the statement said.
"We then referred that report to both the FWC and the Royal Commission.
"The Royal Commission commended the TWU for the way it handled this matter."