Why do cars left on the side of the highway in South Carolina have bags or shirts or cloth hanging out of the window?

Why do cars left on the side of the highway in South Carolina have bags or shirts or cloth hanging out of the window?
The reason that cars on the side of the roads have a scrap of whiteclothing or a bag hanging out is to let people know that this isnot an abandoned vehicle. Some people also do this if they aregoing hunting and leave their car.