Police have located a car belonging to Wendy Hansen, 63, at a train station in Brisbane's north.
But authorities still do not know how or why the woman went to the popular NSW holiday destination of Coffs Harbour, some 800km away from her home of Monto, a small town west of Bundaberg.
Ms Hansen's partially buried remains were found by volunteers clearing vegetation in dunes at Jetty Beach in Coffs Harbour in June.
The car found by police on September 7 - a 2007 two-door Mitsubishi Pajero - was last seen heading south on Queensland's Bruce Highway north of Brisbane on February 29, the day she disappeared.
Ms Hansen was seen withdrawing cash from an ATM in Monto, about 400km away from where her four-wheel drive was captured on CCTV, earlier that same day.
The car was found in the car park of Brisbane's Geebung Railway Station.
Homicide detectives investigating the suspicious death hope to work out how and why she got to the beach town without her car, issuing another appeal for information on Wednesday.
Ms Hansen's partially buried remains were found in dunes at a beach in Coffs Harbour in June (Dean Lewins/AAP PHOTOS)
Police are particularly interested in dashcam vision or information about Ms Hansen or her car's movements between February and June.
"The highly unusual disappearance of a loving grandmother, who has been found 800km from home and no one knows why," Detective Superintendent Danny Doherty said, summing up the case in August.
"The trail goes cold from the Sunshine Coast … we'd like to solve that mystery and provide the answers to the family."
A number of items including clothing, jewellery, reading glasses, a book, a backpack and a wallet were also recovered in June's grisly beach find.
But detectives still have not found a number of Ms Hansen's personal items including her phone, which they said heightens suspicions surrounding the incident.
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