[5] The C209/A209 CLK is based on the Mercedes W203 C-Class platform, and uses rack-and-pinion steering, instead of the recirculating ball design from the previous generation.

[9] Convertible CLK models feature a three-layered electric soft top, that can be operated via the keyfob or at speeds up to 8 km/h (5 mph) in 20 seconds.

[15] Elegance models feature green-tinted glass, a grey coloured grille, 7-spoke polished 16-inch alloy wheels, and wood interior trim, while Avantgarde models featured blue-tinted glass, a black coloured grille, 5-spoke 18-inch alloy wheels, aluminium interior trim, as well as stiffer springs, thicker anti-roll bars, and a 15 mm (0.6 in) lower ride height.

[16] In 2005, a Sports edition, based on the Avantgarde specification, was introduced and featured six-spoke 18-inch alloy wheels, cross-drilled brake rotors, and bi-xenon headlights.

[17][18] An AMG Sports package was also available, featuring a restyled front bumper, a spoiler lip on the boot, and 18-inch wheels.

[25][26] Additional features also include a manually adjustable suspension system designed and manufactured by KW, a limited-slip differential, larger air intakes, bucket seats, 19-inch alloy wheels, a spoiler, diffuser, and wider fenders made of carbon fibre.