This was called a vent window, sometimes a wing. Its purpose was to deflect the wind when you had the window down. Perhaps to influence more car buyers to select the A/C option, auto makers phased out the vent window in
Every one of my kids wore cloth diapers and rubber pants. Before the day of disposable diapers, cloth diapers were pinned on and then covered with waterproof pants which were referred to as "rubber pants.