The mother of murdered Becky Godden has said she is confident her daughter's killer will be found following a new appeal made by police.
Miss Godden's remains were found at a farm in Gloucestershire in 2011, eight years after she disappeared.
Karen Edwards said: "I believe whoever did this terrible crime will be convicted for her murder."
A man who led police to her body was not prosecuted after a judge ruled police ignored arrest guidelines.
Miss Godden was 20 when she was last seen on 27 December 2002 and there are no confirmed sightings of her since 2003.
Her remains were unearthed at Baxter's Farm, Eastleach, following the arrest of taxi driver Christopher Halliwell over the disappearance of 22-year-old Sian O'Callaghan.
Halliwell, 50, later pleaded guilty to murdering Miss O'Callaghan after picking her up in Swindon, Wiltshire, and is serving a life sentence.
The father of three also admitted killing Miss Godden, who was last seen in Swindon in December 2002, but his confession was ruled inadmissible by a judge because a detective had breached his rights.
On Tuesday, police asked for information on a silver Volvo, believed to have been in the Swindon area in 2002-03.
Since then several calls have been made to police about sightings of Becky, although none have yet been made concerning the car.
Mrs Edwards added: "Progress has been made since Sean Memory [the lead detective] took over the case.
"I feel it's going exceptionally well, he's the type where no stone is left unturned."