Florida based tuner RENNtech is offering a new upgrade kit for the Mercedes CLK 63 Black Series which consists from various aerodynamic improvements made from carbon fiber.
The elements includes in the kit are a full carbon fiber front splitter, a rear diffuser, a DTM style rear wing, plus a Carbon
air box with vacuum chamber and front carbon brake air ducts.
These RENNtech upgrades fitted on the Mercedes CLK63 Black Series enable the German sports car to brake better, handle better, and even develop an additional 10 horsepower.
For pricing and additional details on each of these RENNtech upgrades available for the Mercedes CLK63 Black Series check out the official press release below. 
 
RENNtech press release :
Until only recently, RENNtech has offered a line of proprietary, one-of-a-kind carbon fiber aerodynamic upgrades for the CLK Black Series to a small number of exclusive clientele; one of the first being Indy Car driver Tony Kanaan. We recently finished yet another complete package installation and are proud to announce them to market due to the increased interest and popularity of these products.
Our CLK 63 Black Series carbon aero upgrades include our proprietary full carbon fiber front splitter, rear diffuser, DTM rear wing, Carbon air box with vacuum chamber and front carbon brake air ducts. All of our components are manufactured in high quality, full carbon fiber available in either matte or gloss finish to suit individual desires.
These components are the result of countless hours of design and testing by our in house design and engineering staff to integrate seamlessly within the original body work and offer significant improvements in vehicle performance and handling.
Carbon Front Splitter: Our front lip spoiler offers aggressive front end styling and increased down force for improved handling. Integrated into the flat panel underbody tray are functional channels which allow cooling air to be directed to the front brakes to significantly increase brake cooling and reduce heat fade and pad wear.
Price $2450
Carbon Front Brake Air Ducts: Our front brake air ducts were designed in conjunction with our front splitter to dramatically increase cooling air flow to the front brakes reducing brake fade and pad wear under the most extreme driving conditions. These bolt on components require no modification to the brake heat shield and are crafted in full carbon fiber.
Price $1250
63 Carbon Air box: Our redesigned full carbon air box incorporates a restyled carbon vacuum chamber box. By optimizing the path and increasing the volume of incoming airflow, our carbon air box is able to offer gains up to 10 hp, in addition to serving as an attractive under hood showpiece.
Price $2795
Carbon Rear diffuser: Our rear diffuser is the companion component to the front splitter and functions to decrease drag and increase down force by improving the underbody airflow and its transition to ambient air. As with the front splitter, our diffuser is the result of countless hours of design and testing, but isn’t just for looks. Integrated into the true double decker rear diffuser are air channels to dramatically reduce turbulent underbody air as well as a dedicated channel to direct air to the rear differential oil cooler, thus decreasing thermal stress on drive line components and allow for significantly cooler operating temperatures
Price $3250
Carbon DTM Adjustable Rear Wing: Offering aggressive styling and functional performance; our fully adjustable DTM style rear wing is designed to work in conjunction with the OEM lip spoiler and improves rear down force and stability at higher speeds.
Price $3350
Front & Rear Adjustable Camber Bushings: Our proprietary rear suspension bushings
allow drivers to adjust their car’s handling for different tracks and styles of driving, ensuring that the car’s tires maintain maximum grip for proper alignment, better braking, and improved cornering.
Price: Front $1250    Rear $945

Source: Renntech