The Mercedes-Benz A45 AMG W176 arrived in 2013 as a very different kind of hot hatch: not just a faster A-Class, but AMG’s first serious move into the compact performance class. Its headline was the hand-built M133 2.0-litre turbocharged four-cylinder, producing 265 kW / 360 PS / 355 bhp and 450 Nm, sent through a…