"Sandusky Register," March 1920.

From Smithsonian‘s Paleofuture blog, which presents a brief history of the first car phone, or “the portable stovepipe wireless telephone”:

“An article in the March 21, 1920 Sandusky Register in Sandusky, Ohio retold the story of a man in Philadelphia named W. W. Macfarlane who was experimenting with his own ‘wireless telephone.’ With a chauffeur driving him as he sat in the back seat of his moving car he amazed a reporter from The Electrical Experimenter magazine by talking to Mrs. Macfarlane, who sat in their garage 500 yards down the road.

A man with a box slung over his shoulder and holding in one hand three pieces of stove pipe placed side by side on a board climbed into an automobile on East Country Road, Elkins Park, Pa.

As he settled in the machine he picked up a telephone transmitter, set on a short handle, and said:

‘We are going to run down the road. Can you hear me?’

Other passengers in the automobile, all wearing telephone receivers, heard a woman’s voice answering: ‘Yes, perfectly. Where are you?’

By this time the machine was several hundred yards down the road and the voice in the garage was distinctly heard.

This was one of the incidents in the first demonstration of the portable wireless telephone outfit invented by W. W. Macfarlane, of Philadelphia, as described by the Electrical Experimenter.”