Mercedes is blowing the roof off of their AMG GT sports car. Revealed yesterday were the GT Roadster and GT C Roadster models. Both share the 4.0L twin-turbo AMG developed V8, but the GT C boosts the GT's 476 hp to a massive 557. Torque is increased from 480 to 501 lb-ft. Both route power through an AMG Speedshift seven-speed dual-clutch transmission.

The new convertible top has a magnesium structure to reduce weight, and can be opened or closed at speeds up to 50 km/h. The optional AMG sports seats can be fitted with Mercedes' air scarf to keep the occupants warm with the top down. To further help reduce weight gain, the trunk lid is also made from carbon-reinforced plastics. The side skirts are thicker metal, the dash support has additional bracing, and are additional braces and cross members to make sure that the lack of roof doesn't hurt the rigidity of the car. The roadsters get the GT R's active air management system. This has grilles behind the front fascia that open and close to reduce drag and increase underbody airflow, or increase engine cooling, as required.

The GT C steps up the standard roadster with some of the new performance features from the AMG GT R. It has an electronically controlled locking rear differential and a performance AMG exhaust. It gains AMG Ride Control adaptive damping, active rear steering, and adds race mode to the transmission. The battery is a lithium-ion one to save further weight. On the inside, the GT C is more luxuriously appointed, with Nappa leather seats and microfibre accents.