Early attempts to produce the flying car we were supposed to have by now

Hobbes: "A new decade is coming up."

Calvin: "You call this the future?? HA! Where are the rocket packs? Where are the disintegration rays? Where are the flying cars?"

~ Bill Watterson, Calvin and Hobbes (wiki) December 30, 1989

Mark my word: a combination airplane and motorcar is coming. You may smile, but it will come. 

~ Henry Ford, 1940 

By 1953 motor-cars will be obsolete, because aeroplanes will run along the ground as well as fly over it.

~ Sir Philip Gibbs,  1928.

Instead of a car in every garage, there will be a "copter". These tiny "copters", when school lets out, will fill the sky as the bicycles of our youth filled the prewar roads.

~ Harry Bruno, 1943

Weren't we supposed to have flying cars (wiki) by now? Below are some early attempts:

Nov 1947:

A ConVair Car Model 118 flying car during a test flight. The hybrid vehicle was designed by Theodore P. Hall for the Consolidated Vultee Aircraft Company of San Diego, California, but never went into production. A test pilot had to make a crash landing after the vehicle unexpectedly ran out of fuel — he'd been reading from the car's fuel gauge, not the plane's. 

 April 1924:

A car with wings and a propeller protruding from the radiator grille drives through Times Square, New York. It was the invention of A.H. Russell of Nutley, New Jersey.

1928:

An aerocar, unconfirmed as being able to fly, which had a triple function: a combined car, airplane and boat.

Jan. 1946:

Ted Hall's NX59711. It had a top road speed of 60mph and flight speed of 110mph. Hall developed it as a design for paratroopers and commandos.

Lots more at Mashable, Daily Beast, and Smithsonian.