Ahead of next month’s official unveiling at the Detroit Auto Show, BMW leaks some choice imagery as well as the specifications to its 2015 M3 and M4 models. On the outside each sedan sports a subtle power dome in its hood, M3/4-branded strakes on each front fender, split-five-spoke 19-inch wheels, and carbon-ceramic brakes. Under the hood, both cars pack a 430-horsepower, twin-turbocharged six-cylinder engine with the choice of a six-speed manual or a dual-clutch transmission. The cabin of the M3 and M4 will include a new steering wheel, bolstered heated seats, carbon fiber trim availability, side and top-view cameras, and LED lighting. Lastly, both models will be available in different color options.