Assuming the standard meaning of the phrase "snake-oil salesman", I think the odds that this is all an elaborate sham to knowingly dupe people into buying a product that doesn't exist converge on zero.
But, the case can certainly be made that he is prone to hyperbole and "exuberant optimism".
Is that too high or too low?
There's a 0 percent chance he's a snake oil salesman. There a reasonable chance his company won't succeed because of a problem making the cars cheap enough. But still they are awesome cars. Pretty soon they will be the only company in the US that has sold enough EVs that the tax credit runs out. That will really piss off the tesla haters who will have one less reason to claim it's all a gyp or whatever.
He's not a snake oil salesman, but he could be over his head in this one.