That's the problem with exponential development. It seems like you're getting nowhere for decades, then all of a sudden it's starting to amount to something, and in the span of maybe a year or two it goes from impractical to plausible to obvious and ubiquitous.

The problem with predicting these curves is there's usually a confluence of factors that lead to that tipping point. When the right algorithms, hardware, and software are combined it'll be obvious in retrospect, but right now we're still fumbling around with primitive solutions.

When will there be a TPU-type device suitable for in-car use? When will there be adaptive deep-learning algorithms available that can work in the demanding real-time environment of a vehicle? When will enough testing be done that we know such a solution can work without endangering people?

It will happen, but pinning down when is very hard. You'll only know when you're close, and by then you're already flipping from impossible to inevitable.