Okay, this is ridiculous.
When you take your dog along for a ride, but prefer not having it inside the car, it can ride safely and comfortably in this sack, which is carried on the running board. The bottom of the sack is clamped to the running board and the top is fastened to the lower part of an open window with hooks, covered with small rubber tubing to prevent marring the car.
It can't really be expressed in a text description. See the image at Dog Rides Comfortably in Sack on Running Board.