Three Girls in the Desert

A blonde, brunette and redhead are in a desert. The brunette says, "I brought some water so we don't get dehydrated." The redhead says, "I brought some suntan lotion so we don't get sunburned." Then the blonde says I brought a car door." The other girls said, "Why did you bring that?" Then the blonde says, "So I can roll down the window if it gets hot."