With some option boxes checked off—Sport Package and Sport Touring Package, specifically—the M56 S is a car that can go toe-to-toe with some of the best luxury sport mid-sized sedans. It's more powerful than the rest, has a naturally aspirated engine, and has handling that will put a smile on your face. It doesn't have as many options of MB or BMW, and its gas mileage is not the best, but if the MPG is a problem, there's always the cheaper M37...