He had previously pleaded guilty to 11 charges of breaching the Fair Trading Act, and his co-accused MAC Warranties Limited, of which he is the sole director, to 17.
The case involved at least 79 instances of repossessing cars sold on credit when their payments were defaulted on.
The cars were then on-sold at an undervalued price to other companies which Spiers was then a director of, and the balance was subtracted from the defaultee's outstanding loan, the court heard yesterday.
The scheme was described as a "car-go-round" by Commerce Commission staff.
In some cases cars were bought as 'wrecks' under the premis of on-selling them to a scrap metal dealer, only to wind up 'reconditioned' back on the forecourt at Spiers' car yard at a price far higher than what was paid for them.
"This business made and broke its own rules when it came to vehicle calculations for repossessed vehicles," Commerce Commission lawyer Alysha McClintock said.
In some cases, vehicles were hurriedly valued internally by Spiers and his staff using Turner's car auction templates to give the impression they were valued independently, Ms McClintock said.
When the revelations came to light through a Fair Go investigation, Spiers claimed the vehicles were valued through a reputable, third-party organisation - specifically Turners.
However, after the Commerce Commission issued a search warrant, that was found not to be the case.
A veneer of independence was used with the media and the commission, Ms McClintock said.
In some cases the repossessed vehicles were not even valued internally, and Spiers and his staff would simply ascribing a value to them, she said.
"It was difficult to see how debtors received the best price for the vehicles when the processes fell so short of the mark."
The commission accepted the company had now changed its systems.
The offender's lawyer Jenny Stevens said they very much regretted that they were before the court yesterday.
"And they do unreservedly apologise for any stress caused to the debtors who are very much valued customers.
"We do accept that there was not the necessary checks and balances."
Spiers was not present in court.
The offenders pleaded guilty at the very first opportunity and had offered compensation to the victims, Ms Stevens said.
All cars that were repossessed now were independently sold at auction, she said.
Judge Philippa Cunningham reserved her decision regarding the offenders' sentence until April.
- APNZ