Thieves made off in a stolen car after it was left unattended while defrosting in Sully.
The unattended vehicle was taken from a driveway on South Road at around 7.30am on Wednesday morning, while it was left to defrost with keys in the ignition.
It was last seen being driven towards Barry.
A South Wales Police spokesperson said: "While it is understandable in the current cold weather, motorists are advised not to leave their vehicles unattended and to exercise caution when leaving keys in the ignition."
"Unfortunately, there are opportunist thieves who will take advantage."
Anyone who may have noticed any suspicious activity in the area or who may have CCTV or dashcam footage should contact South Wales Police on 101 or use the live web chat, quoting reference no. 2500006845.