A man on a snowscooter spotted the top of the car on a deserted and snow-filled forest road, near the northern town of Umeaa.
"He saw movement and realised there was probably a person in there and called the police," said Ebbe Nyberg, a duty officer in the northern Vaesterbotten county.
He added: "They were amazed at what they found: A man in his mid-40s huddled inside in a sleeping bag "in really bad shape," starving and barely able to move or speak."
Temperatures in the area have recently plunged as low as -30C (-22 degrees Fahrenheit).
The man, who had not been reported missing and who has yet to say how he got stuck, appeared to have survived on nothing but snow since mid-December.
After being rescued, he was rushed to the Norrlands University Hospital. His current condition is unknown.
