Vaporware indeed. When one looks at the financials of Tesla, it is difficult to see how Tesla can develop and produce the "Y" Model let alone the Model 3, and in no way simultaneously. Tesla is saying it is going to produce and sell at a profit the Model 3 for $42,000 (average transaction price per Musk) when it can't produce and sell the Model S and Model X at a profit at nearly a $85,000 transaction price. Tesla loses billions of dollars a year, and has never made a profit. At some point it has to make a profit. For Tesla to build the Model 3 and sell it for $40K less than the Model S, it will have to completely redesign the Model 3 chassis and production process; it is not going to get the cost out of the battery since the battery doesn't even cost $40K to build. Tesla hasn't even recovered the development costs for the Model S. The Model X, which is heavily based off the Model S chassis was originally supposed be priced $20K lower than the Model S, but it isn't. The X-wing doors, pedestal rear seat, and other engineering challenges cost the Model X 2 years in production delays. Two years of delay costs real money, which must be recovered in the sale price.
Now Tesla has to invest in designing a new lower-cost-to-manufacture Model 3 chassis, and tool its plant to build the cars in volume production of over 100,000 cars per year. The old NUMMI (Toyota/GM) plant was capable of building 500,000 cars a year Musk says, but that was building one car model with a few different trim levels for the Toyota Matrix and Pontiac Vibe. Tesla will be building 3 different models, with just two based on the same chassis design. It's tough to believe.