So far the Mercedes-AMG GT R is the wildest road-legal Mercedes in production right now but if you have the ‘regular’ AMG GT you can turn to tuning house Piecha Design for their new RSR upgrade package. Visually you get a new aerodynamic kit which makes it as aggressive looking as the GT R. Complimenting the visual mods you are able to choose from some performance kits too. Piecha has developed an ECU power module that pumps power up to 612 horses and 840 Nm of torque, taking it way past the 577 hp mark of the AMG GT R.