Lynda Spence, 27, was last seen when she visited her parents' flat in Glasgow's Partick on Wednesday, April 13.
Police say her mobile phone was discovered in Kilbirnie, Ayrshire Kilbirnie, on Thursday June 2.
Her silver Vauxhall Astra car was also spotted in Ayrshire – on the A77 at Floak – on Wed-nesday April 20.
Today her parents Patricia and James have been left distraught by her disappearance and are due to make an appeal in Glasgow.
Ms Spence, also known as Lynda Zefaj or Lynda Palmer, who lives in Castlebank Street near Glasgow Harbour, is being urged to get in touch.
The day after she disappeared her mother received a text from her daughter's phone saying she had gone to London.
Officers are now trying to trace her recent activity.
It is thought that Lynda may have been involved in property deals which went wrong.
Leading the probe, Detective Superintendent Alan Buchanan, said: "As each day goes by, we are becoming increasingly concerned for Lynda's safety. She has not been missing before and it is out of character for her not to contact family.
Lynda is 5ft 8in tall, and wears her brown hair in a ponytail.
She is tanned, has a scar under her eye and is known to frequent Glasgow's West End and parts of Ayrshire.