The Audi is among four European cars caught in the High Court's freezing orders. A 2014 Mercedes Benz CLS 350 and 2005 Bentley Continental are also frozen.
The Mercedes has an estimated value of $85,000 and finance of $58,600. The Bentley has an estimated value of $85,000 and finance of $33,000.
The Robertsons also applied to the court to have the receivers removed, for the FMA to pay $115,000 of receivership fees and for jewellery and household effects to be returned.
Justice Anne Hinton, in her decision, said some of these items in the Robertsons' weekly budget were "extraordinary" although she allowed the family a total of $4765 for expenses and their mortgage each week until December.
The family's home was the most valuable of the $1.6 million worth of frozen assets and the judge suggested it could be sold and its mortgage repaid. There is also a proposal to sell the Bentley and Mercedes, which could realise about $70,000.
The judge thought it would be inappropriate to return passports and to terminate the receivership this early in an investigation, but deferred the question of who pays for their fees. She ordered the return of some personal effects to the couple. Last month a wedding ring thought to be worth $92,000 was returned to Lisa Robertson.
Before the hearing, the receivers filed a report recommending PTT and three of its related companies be put into liquidation.
The report also said that Robertson was the moving force behind the business activities at issue.
"These were conducted through the first to fourth respondents ("the PTT Group") and principally involved the provision of trading signals to clients. Mr Robertson provided the signals personally, apparently without any formal qualifications or relevant experience. Mr Roberson was, on examination, unable to verify the accuracy of promotional figures advertising returns, and confirmed they were not based on his own trading results," Justice Hinton said when referring to the report.
Between 2013 and August 2015 the PTT Group generated $4.44m in deposits from third parties.
The receivers estimate those deposits comprised product sales of around $1.87m, but also $2.57m from other sources, such as sale of shares and accepting money from clients.
"The business purpose for the loans and share purchases remains opaque," the judge said.
Given PTT and the associated companies received between 2013 and 2015 of over $4.4m, the judge said "the net worth of all respondents of approximately $1.6m appears very low".
The receivers' report, according to Justice Hinton, said the assets of Lisa Robertson and the couple's family trust "appear to have been funded at least in part from, and now represent the most substantial assets of the PTT Group."
Read the full decision here