Answer: The Dashboard
In modern cars, the dashboard is a flat surface inside the car, under the windshield, which seems to exist only for the purpose of creating space so that your face is not pressed against the windshield glass (and to give bohemian passengers a place to throw their boots).
Historically, however, the board was not a flat surface for throwing newspapers and parking tickets; It was a vertical barrier at the front of a carriage between the driver and the horses. Whatever the helmets of the horses that rushed from the road (mud, sticks or manure), the driver diverted him from the board.
The board is not the only remaining component of the carriage days. Once upon a time, the trunk was not a distinct storage compartment, but a literal trunk attached to the back of the car.