While it's a fake, it's a relatively well-done fake. The page mimics the style of Chevrolet's own site, and the renderings are versions of the Chevy Tru 140S concept from 2012. There's a color picker, made-up specs, and even a promise of apps. People love apps! The perpetrator even went for completeness by creating Facebook, Twitter, and Instagram accounts for the Jolt. The social timeline reveals that the site was down for a time due to overloaded servers – probably not an issue GM would face for an unannounced product.
The question now is who would do such a thing? We tried to find out who owns and controls the site, but a Whois search just shows that chevyjoltev.com was registered through GoDaddy on March 10, 2016. (It's very easy to mask the identity of the owner of a domain name, incidentally.) Then someone found a hidden page on the site made by its creator, a guy named Matt Teske. (Hat tip to Twitter user @Hoonable.) Matt really likes small front-drive GM cars and claims in his explanation of why he built the site that his personal Cavalier Z24 influenced GM in some way to do, uh, something with small cars. He's a branding and strategy guy by profession and apparently has too much time on his hands.
Now that his identity is no longer secret, we have a feeling GM will be sending him friendly cease-and-desist letter, given the amount of trademarked material being used – logos, tag lines, that sort of thing. Hopefully we'll get the story, but for now we're going to think of other car names that end in "-olt".