I've seen something similar here in the United States,years ago my Grandfather used a piece of cardboard to help keep the heat in the radiator. HRP
Not that long ago but, when myself and a buddy went on the Hot Rod Magazine Power Tour (97) we used the cardboard trick while going through the Rockies, worked great.
Pines Winterfront came up with a better idea for the 32 Fords that had to go regardless of how cold the weather. HRP
Probably local made, cardboard works until it gets wet but is easily replaced. It looks well made and I bet the Winters in Norway demands something sturdier than cardboard.
My mom used to call those a sweater when I was little, the ones that looked like window blinds she called a turtle neck. I have seen them on old Fords before but not since I was a little guy. They still use something similar on Diesel trucks