2015 BMW M4 CONVERTIBLE: While at the 2015 Chicago Auto Show, you might hear the slogan for the new BMW M4 convertible that goes, “Top down. Heart rate up!” This year is the first that the M4 hardtop convertible will be on display, and it contains the equipment to interest new drivers and loyal enthusiasts alike. The sleek exterior features optimized aerodynamics includes an air curtain in the front apron and air breathers behind front fenders with integrated M side gill and M4 badging. With a push of a button, the M4 transforms from a sporting coupe into an elegant convertible in a 20 seconds, even when traveling at speeds of up to 11-mph. The standard 3.0-liter, racing-inspired M TwinPower turbo inline six-cylinder engine pumps out a respectable 425-horsepower, and can be order with the standard six-speed manual gearbox, or the optional seven-speed M Double Clutch automatic with Launch Control for optimum acceleration. With the wind blowing through your hair, the M4 droptop dashes from 0-to-60 mph in 4.4 seconds, which drops to 4.2 seconds when the vehicle is equipped with the seven-speed transmission. On track top speed is 155-mph. Bringing the 4100-lb vehicle to a quick, smooth stop are disc ventilated, M carbon ceramic brakes. A new feature is the neck warmer vents located below the front seat headrests that blow warm air onto the front passengers’ necks. With the hardtop open, there is 7.8 cubic feet of space in the trunk that increases to 13 cubic feet when the hardtop is closed.