Kankamol Albon, 41, lived in 14th century Smallbridge Hall, a £4 million 10-bedroom property in Bures, Essex. The mother of five educated her children at private schools while living a life "that few could aspire to", taking expensive overseas holidays.
When Albon came under suspicion more than three years ago, she claimed that she was being blackmailed into selling Ferraris, Porsches and Mercedes at below market value. Julian Christopher, prosecuting, told Ipswich Crown Court that Albon would keep the money paid to her by clients for their cars.
Between July 2007 and the end of August 2008, the car dealership was operating at a loss, with Albon selling cars for less than she paid for them.
The fraud worked thanks to a high turnover of cars and new clients were persuaded to pay immediately for their cars with the money used to cover existing shortfalls.
Mr Christopher said Albon had effectively run a Ponzi scheme. He said: "In order to carry on trading, Albon persuaded customers to pay upfront for cars she was buying for them and to invest in other car purchases by offering them a share of the profits. As her losses grew, so did the need for further investors and customers."
The business collapsed in August 2008 with losses to investors amounting to £7.5 million and Albon was arrested in February 2009.
After her arrest she operated a VAT fraud while on bail in 2010 and last year, fiddling the taxpayer out of £1.8 million. HM Revenue and Customs investigations revealed that 107 of 122 vehicles she claimed to have bought were fictitious, with false documents used to cover the fraud. Albon claimed she had sold expensive cars to overseas buyers before claiming back the VAT paid on them.
Investigators discovered that there was no evidence of the cars ever being sold and any exports taking place.
She admitted charges of fraud by false representation in April and last week admitted the VAT fraud. She was jailed for six years on Wednesday.
Judge Rupert Overbury said the frauds were designed to prop up a failing business and to maintain Albon's way of life.Her home has been repossessed and is for sale at £3.9 million.
Speaking afterwards, Bob Gaiger, from HMRC, said: "Kankamol Albon had a lifestyle that few people could aspire to. She owned a moated house, took expensive foreign holidays and sent her children to private schools.
"This was partly paid for using the proceeds from her crime. Her luxury car dealership was a cover for a large-scale VAT fraud."
DC Adrian Finbow, from Suffolk Police, said investigations had been frustrated by Albon's "lies and deliberate attempts to change the direction of the investigation by pointing the finger of blame at others".
He added: "However, we are satisfied that she acted alone and her sole motivation for the fraud being one of excessive greed, and the desire to buy expensive luxury goods and live an opulent lifestyle.
"We hope the sentencing will bring some sort of closure to the victims, some of whom have lost their homes and businesses."
Kevin Baumber, mitigating, said the business had been run legitimately for many years but had got into difficulties after losing millions of pounds in a foreign business venture.
Proceedings will be initiated under the Proceeds of Crime Act 2002 to identify and confiscate any assets gained through criminal activity.
