> If you can get a megawatt into the car batteries without setting them on fire, that's game over for petrol cars

Chinese people are complaining about this. In highway service stops, the megawatt charger is too fast, the 20%-95% charging is done before people returns from the toilet. Realistically, the charging speed should take around 10 minutes in average for everyone.

Or there could be some price surges. You are in a really hurry pay some 1.2x price for 3 min megawatt charge, or flat price for a regular 10 min charge.