A metallic grey Audi A5 was stolen from an address in Blanefield at about 7am on Monday, January 23.
The thief “fished” the keys for the car through the letterbox.
The police are appealing for anyone who saw anything or anyone suspicious in the area about this time to contact 101.
Sergeant McNally, of Balfron Police Office, said: “Residents should be reassured that this is an isolated incident, however sensible precautions must be taken. Do not leave car keys lying in visible and easily accessible places in your home and ensure your home is properly secured.
“On cold mornings like today, never leave your car running unattended to heat up. Be vigilant. If you see anything you are suspicious of, contact police immediately.”