The sliding rear window on a pickup truck. Your beer cans/bottles are not considered open containters when they are in the bed of your truck.
Dude, chuck your brew through the beer window when you are done with it.
The sliding rear window of a truck allowing easy access to the beer cooler up against the front of the truck's box and also allowing any passengers in the cab of the truck to dispose of their empty beer cans or bottles into the box of the truck without littering
Dude, will you reach thru the beer window and grab me a cold one from the cooler.