Kornbluth, visionary

In 1951, Cyril Kornbluth wrote a short story where a fellow ended up way in the future. A future populated by morons, because intelligent people breed less.  A future with passenger cars

Swept-back lines, deep-drawn compound¬† curves, kilograms of chrome. He ran his hands over the door- or was it the door?-in a futile search for a handle, and asked respectfully, “How fast does it go?” The psychist gave him a keen look and said slowly, “Two hundred and fifty. You can tell by the speedometer.”

Except that

Barlow began to wonder if he knew what a kilometer was, exactly. They seemed to be traveling so slowly, if you ignored the roaring air past your ears and didn’t let the speedy lines of the dreamboats fool you. He would have sworn they were really crawling along at twenty-five, with occasional spurts up to thirty.

The future is here.