The secret, Hotz adds, is that Comma One gets data from its video feed. "Even Tesla isn't doing that," he says. And importantly, it's using commodity components that should help it get to market quickly. The entrepreneur notes that many would-be rivals don't even have hardware to show, let alone a concrete plan to ship products.

It's easy to remain at least a bit skeptical. Comma.ai is moving very quickly, and Hotz is quick to admit that the Comma One would only arrive this year in "very limited quantity" at best. You'll probably have to wait until 2017 to retrofit your car, and it's hard to say how well Comma One will work when it's ready. If it comes anywhere close to the hype, though, it'll be a big deal -- it's a readily available, vaguely affordable add-on that will give you a taste of the self-driving future without forcing you to buy a new car.