A couple who advertised their BMW car online had it stolen at knifepoint after thieves posed as private buyers.
Police said the black BMW 1 series, with registration plate NJ12 NUC, was taken from a driveway on Glasgow Road in Paisley at about 14:50 on Monday.
One of the thieves took the car for a test drive before another man appeared and pulled the knife on the sellers.
They made off with the car, leaving its owners - a 58-year-old man and a 54-year-old woman - in a state of shock.
Police said the couple had recently advertised the car on a number of online classified and marketplace websites before the theft took place.
They had gone on a test drive around the local area with what they thought was a prospective buyer before returning home and finding another man waiting.
Detectives said he produced a knife and threatened the couple before both men made off in the car towards Hawkhead Road.
Both suspects are described as being white Scottish men, aged between 20 and 25 and about 5ft 8in in height.
One of the men had a slim build and short dark hair and was wearing a luminous green hooded top, navy trousers and trainers, described as being nylon.
The other man had fair hair, shaven at the sides and longer on the top.
He was wearing a grey bomber jacket with the jacket zipped up and was wearing dark jeans.
Det Con Jamie Howarth said officers were assessing CCTV to find those responsible.
He added: "We are still working to trace and recover the vehicle and I would ask anyone who encounters a black BMW 1 series with this registration to contact police.
"This was a despicable robbery, which took advantage of the fact that the couple were attempting to sell their vehicle online.
"The owners were engaging with the suspects in good faith who have then twisted this against them. They were taken entirely unaware and no amount of vigilance on the part of the sellers could have prevented this callous robbery."
Police described the incident as "isolated" and said there was no suggestion that other crimes of the same nature had occurred.