Barb and I had a few hours off tonight and went to a bookstore, but I'd forgotten my current book. Browsing around I found one from John Seabrook, a writer whose work I really enjoy; I know him from his articles in the New Yorker and his book Nobrow.
It was something of a Rube Goldberg contraption. It had twenty-nine moving parts, which meant a lot of potential for breaking down. When the driver accelerated, the vacuum was insufficient to run the intermittent mode, and the wipers would default to high speed. Trico [the manufacturer], in trying to sell the wiper to Ford, advertised this as a specially designed passing feature -- useful, say, in overtaking a truck on a rainy day. "The engineers saw it for what it was, which was a design flaw," [Ford engineer] Daykin said. "But the planners thought that the passing feature was really neat."
How many times have you seen software do the same thing? We even have a saying for it, the sarcastic: "It's not a bug, it's a feature."