The last the world knew of Pia Farrenkopf, she had withdrawn $1,500 from her checking account in February 25, 2009. Friends and family didn't see or hear from the woman they described as fun and intelligent in the years since, but they chalked it up to Farrenkopf's solitary tendencies. Meanwhile, letters piled up in her mailbox in the middle-class neighborhood where she lived in Pontiac, Michigan, before being taken back to the Post Office as unclaimed. Mummified: Pia Farrenkopf, who was 44 when authorities believe she died, sat for five years in the backseat of her car mummified . A family member even tried to phone in 2012 to tell Farrenkopf her mother had died, but never got a response. Mortgage payments kept being deducted automatically from bank accounts flush with cash from Farrenkopf's job at ALLTEL Information Services, where she had once programmed banking software. It was not until the money ran out in 2013 and the bank foreclosed that Farrenkopf was finally discovered. The Detroit Free Press reports two repairmen, hired to patch a hole in the roof, found her in 2014, slumped in the backseat of the Jeep Liberty parked in her garage, mummified. Investigators later noted she was found surrounded by hundreds of unopened letters and several empty packs of cigarettes. She had $500 in cash in her pockets and a partially drank bottle of wine by her side. Detectives couldn't find a single fingerprint on the bottle. The home was in a state of chaos and disrepair - a far cry from the way her friend Joan Gill Strack said Farrenkopf liked to keep her home. Scene: Neighbors said they helped clear the driveway and mow the lawn while they believed Farrenkopf was still in the home, though many eventually moved away . World traveler: Farrenkopf traveled to England and Scotland, as well as around the United States, while working programming banking software for ALLTEL Information Services . 'Her house was well-kept, very clean, very tidy,' Strack said. 'She liked things picked up and ordered.' But police found the floors littered with empty soda bottles, more unopened mail, loose clothing and refuse. Black mold had invaded after the sump pump broke down, with dark spots dotting the walls. Strack, who had worked with Farrenkopf when the two lived in Little Rock, Arkansas, said she was 'fun to be around' and 'very, very good at her job,' and traveled to Scotland and England and throughout the US for work. Still, Farrenkopf was never extremely social. Siblings recalled long stretches of time where they wouldn't hear from Farrenkopf, who would often not  return phone calls. Fun and smart: Farrenkopf, pictured in this undated photo taken at a coworker's birthday celebration, was described as an excellent employee . Mysterious: Darryl Tillery, a neighbor, said he could not have known that the solitary Farrenkopf was in her garage for five years . Then a postcard or call came from a far-flung destination like Austria. 'Sometimes she would go, literally, for years without us hearing from her,' one sister, Jean LeBlanc, who lives in the Boston area near where Pia and her nine siblings grew up, told the Free Press. 'And then all of a sudden, she'd show up, so nobody ever thought anything about it.' Strack remembers how easily Farrenkopf could cut people out of her life when, after a friend showed up a few hours late for a party without calling, she immediately ended the relationship. 'Pia told her she was done with her,' Strack said. 'She didn't speak to her after that.' Strack said her own friendship with Farrenkopf ended in 2001, though she could provide few details beyond saying that they were together too much. Yet Farrenkopf was by all accounts still doing well. She continued working at Pontiac Fidelity National Information Services, where she was an 'exemplary employee,' management told the Free Press. She even began planning to open a small business of her own - a fitness business in nearby Waterford called Slender Lady. LeBlanc, who managed a Curves location in Massachusetts, agreed to travel to Texas with her sister in 2003, where the two attended a two-week seminar on health in preparation for Farrenkopf opening her business. Past due: Bills and letters would stack up in Farrenkopf's mailbox and then be returned to the Post Office unclaimed, a letter carried told the US Postal Inspector in 2014 . Towed: Authorities dragged out the 2003 green Jeep Liberty that once belonged to Farrenkopf where she was found dead and mummified . That plan was never fully realized. Court records showed the owners of the property sued Farrenkopf in 2005 for breaking her lease, though Farrenkopf never responded to the complaint. Credit card companies also initiated three lawsuits against her from 2005 to 2007 over unpaid bills, receiving judgments that added up to over $15,000. Her homeowners association placed liens totaling more than $2,000 against unpaid dues for the association. Farrenkopf wasn't always shut in her home, though it was often unclear where she was. Officers checked on her home in 2005, when neighbors told them they had not seen her in a month. Inside the home, police said they rescued her abandoned cat, Bungie, and white poodle, Baby, but while the pets were kept in a shelter - Baby was later adopted - there's no evidence Farrenkopf came to collect them. Sister Mary Mulligan looks over an image of Pia Farrenkopf in the 1983 Cardinal Cushing Central High School, an all-girls Catholic school yearbook in Boston (file photo) In May 2008, she resigned from her job under circumstances that are unclear, then in October of that year, she was cited for driving with a suspended license, expired plates and no proof of insurance. There's no record of Farrenkopf after the 2009 cash withdrawal, and investigators, who checked credit card statements and subpoenaed bank, phone and health records in a 'massively thorough' search say her cause of death is undeterminable. 'There was no trauma to body, so it only leads to a couple conclusions,' Oakland County Sheriff Michael Bouchard said. 'Either it was a medical situation that led to her death or something self-induced.' Medical records showed Farrenkopf, who was 44 when investigators believe she died, smoked more than a pack a day and in spite of being worried about her liver, drank regularly. Other family members dealt with cancer, heart disease, high blood pressure and kidney disease, according to that report. But the tank in the car still had two gallons of gas left, which led investigators to rule out carbon monoxide poisoning and her organs were so mummified, according to deputy medical examiner Dr Bernardino Pacris, making a toxicology report impossible. The case is now inactive, leaving relatives wondering what happened to their sister that would have ended her life quietly and out of sight. 'I just don't understand why anybody would sit in the backseat of their own car. And just stay there,' LeBlanc said. 'Why would you do that?'
Pia Farrenkopf of Pontiac was found mummified in the backseat of her car . Investigators believe she died at 44 in 2009 but it wasn't until 2014 her body was discovered . Relatives and a friend described Farrenkopf, who lived alone, as smart and fun but often solitary . Her remains were in such a state of desiccation that the medical examiner was unable to conduct a full autopsy and the cause of death is unknown . She was only discovered after bank foreclosed on her house .