The 2018 BMW M550i is the quickest 5 Series currently offered thanks to its 4.4-liter, twin-turbocharged V-8 making 456 horsepower and 480 pound-feet of torque – aided by both a smartly calibrated ZF eight-speed automatic and BMW’s xDrive AWD system. At full grunt, the prodigious power will launch the 4,300-pound M Performance sedan to 60 mph in just 3.8 seconds. But that’s not this Bimmer’s coolest feature. No, that goes to its HVAC system with dual fan speeds for the driver and front passenger.