Here's The Problem With Jeep's Recalled Gear Shifter (David Tracy, Jalopnik). See also Consumer Reports' YT video (published May 19, 2016), Fiat Chrysler Recalls Confusing Shifters.
"For a few months in 1922, throngs of America’s youth — from schoolkids to shopgirls — were swept up in a leaderless pyramid scheme that promised “something for nothing” and encouraged promiscuous flirtation. These were the “Shifters.” This is their (brief) story." (NYTimes link) Previously on the flappers and flapper slang: 1, 2.