The days have to be numbered for 630 horsepower road rockets like the MERCEDES-AMG GT 63 S: ADRENALINE RUSH. Grab one while you can, says Road Test Editor Howard Walker. Yes, the day will come in the not-too-distant future, when your electrified cocoon-on-wheels is driving you autonomously to who-knows-where, and you'll smile. You'll smile because you'll remember the time when there were cars in the world like the Mercedes-AMG GT 63 S. You'll remember fondly how, back in 2020, this mighty Me...