Popular Science asked "wouldn't it be great to have a car that changed from electric drive for use around town to gasoline power for highway driving?" and GM answered with the XP-883.
"It makes so much sense," the magazine wrote in July, 1969, "that we feel they're missing a bet if they don't put it in production."
Unlike the Volt or the Prius, it was tiny and light.
Chuck Squatriglia in Wired describes it: "The heart of the car was a 35 cubic inch (573 cc) two-cylinder engine -- small enough to be exempt from the emissions rules of the day -- coupled with a DC motor powered by six lead-acid batteries just like the one under your hood. You could tool around in all-electric mode or in gas-electric mode, according to PopSci. In hybrid mode, the electric motor did all the work to about 10 mph, at which point the gasoline engine took over. If you needed to really get up and go, the engine and motor worked in tandem. Still, the car was as slow as it was advanced. Top speed was just 60 mph, and it needed 28 seconds to get there -- making it only slightly faster than a Citroen 2CV6."