A woman contacted police on Monday and reported that she had been sexually assaulted at about 2.30pm on Thursday, down a side road north of Shawbury.
Following the incident, she told police she ran to the main A53 and flagged down a red car, possibly a hatchback and similar to a Peugeot, driven by a female.
The driver, who would have picked her up near the turning to Stanton Upon Hine Heath, is reported to have given her a lift to the Tern Hill area before driving off along the A41.
Detective Constable Nick Williams, of Market Drayton CID, appealed for the driver to contact police on 0300 333 3000.
“She may have important information which could help our investigation, having apparently picked up our victim and given her a lift following the incident,†he said.
“The woman’s name may have begun with a ‘V’ and she may live in either the Stoke on Tern or Stoke on Trent areas.â€
Anyone else who might have witnessed suspicious activity in the relevant area during that afternoon is asked to contact police on 0300 333 3000 or the anonymous Crimestoppers number 0800 555 111.