I think about natural disasters.

Remember that footage of Japanese drivers fleeing from the tsunami floods? How many more would have died if their cars had been slower? How many more would have survived if their cars could have gone faster?

There are plenty of survival situations (e.g., tsunamis, volcanoes, tornadoes, gas explosions, etc.) in which it's desirable for your car to go a lot faster than one should drive under normal driving conditions.

Sure, but going higher than say 150 km/h for more than 10 seconds the car could phone that in and you'd have to justify it to the police or face a steep fine.

I would never pay a single unit of currency for such a car, even subsidized, and neither would most of humanity, including politicians.

I see plenty of very dangerous driving within speed limits, ie people unable to keep in their lane, playing with cellphone, randomly breaking in semi-empty roads and so on.

These are my experiences from highways from most weekends. In towns, speed limits make much more sense and could be enforced by speed bumps or stationary radars

Why?

Why what?

You have to weight it against the gain at the other end. I'm nearly certain that more lives would be saved from inability to exceed speed limit, than would be lost by speeding away from something.