The pensioner was targeted in Knightswood, Glasgow, as she got into her Peugeot to travel to an appointment on Thursday morning.
The would-be thief fled after she drove towards some workmen nearby and rolled down her window to raise the alarm.
Police are hunting for the man, who struck at around 8.40am in Athelstane Road.
Detective Constable Mark Milroy said: “This was a terrifying experience for the elderly woman and thankfully she was able to seek help quickly.
“Extensive inquiries are under way to trace the despicable individual involved and I would appeal to anyone who noticed a man matching the above description in Athelstane Road prior to the incident, or running along Anniesland Road afterwards, to please get in touch.
“I would particularly appeal to any motorists with dashcams who were in the area this morning to check their footage in case they have captured anything which could be of significance.”
The suspect is described as aged between 35 and 45, around 5ft 7in, of medium build, with short, dark hair and glasses.
He had a local accent and wore a beanie-style hat with a union flag design, a dark waterproof jacket and grey jogging bottoms.
Anyone with information is asked to contact police on 101, quoting incident number 0811 of December 6, or call Crimestoppers on 0800 555 111.