As the sales of Model 3 are at least a good year away (and production not much less) GM is quick to point out (with a video) that preproduction examples of Chevrolet Bolt are already being bult in their factory in Michigan. They said that the production of the cars that can be sold to general public won't start until the end of this year, but the preproduction serves to allow the technicians and assembly engineers to fine tune all the details of production process before it actually begins (and provides cars for testing and publicity purposes).

So Chevrolet Bolt could actually hit the streets before the Tesla Model 3 which acording to Tesla should be in series production in late 2017.