Police officers are searching woodland as they attempt to find the body of Emma Faulds.
Their activity has concentrated on an area near the village of Barrhill in South Ayrshire.
Ms Faulds, 39, from Kilmarnock, was last seen in Monkton on Sunday 28 April.
Officers have appealed for information about vehicle movements on the A714 Girvan to Newton Stewart road on Monday 29 and Tuesday 30 April.
They are particularly interested in Jaguar and Mercedes models.
A man has appeared in court charged with her murder.
Ross Willox, 39, made no plea at Ayr Sheriff Court and is expected to return to court next week.