2021 Mercedes-AMG GLS 63 First Drive

MALIBU, California—If you're the sort of person who sees a new 600-plus horsepower SUV hit the road and asks, "Why?" through a pained expression, well, move along. This is not the car you're looking for. If, on the other hand, you're the sort that considers the concept of a vehicle that seats seven and rips off 4.1-second 0-60 mph runs for a ...