I remember seeing a metal cylinder about 12" in diameter
about 20" long. Make with sheet steel.
that would hang on the RF door window. The way a speaker
would in a drive theater or a car hop would hang the tray
on the window.
The front of the cylinder/tube was open so air would enter
the tube pass over ice then the air would pass through
an opening of the tube on the side near the back.
Cooled air would then enter the car.
I do not know how effective this was or how long the ice
would last. Jeffrey
