Build a luxury hatchback around the most powerful production four-cylinder engine in the world and there you have it, the new Mercedes-Benz A 45 AMG, a compact class first for the brand, packing 360 horses for an electronically-limited 155 mph top speed, 0 to 60 mph in 4.5 seconds, 7-speed sports transmission, front-wheel/all-wheel drive, and a long list of performance, sport, comfort and style features, including ultra-low emissions, plus an extensive menu of options. It goes up against the new Audi S3 Sportback, both officially revealing at the Geneva Motor Show in March. Hot hatch! Expected for July, base price is $TBA (but start thinking around $50,000).