Mercedes-Benz redesigns its CLK coupes and convertibles for 2003, giving the coupe true hardtop styling without middle roof posts. The convertible is due to bow midyear as an early 2004 model. Both come in three trim levels. CLK320s have a V6. CLK500s have a 5.0-liter V8 and replace CLK430s, which had a 4.3-liter V8. CLK55s, developed by Mercedes' AMG performance arm, have a 5.4-liter V8. All use a 5-speed automatic transmission with manual-shift feature. ABS, antiskid/traction control, and front and rear side airbags are standard. Convertible front side airbags cover head and torso. Coupes have head-protecting curtain side airbags. The '03s are slightly larger and some 120-to-250 lb heavier than their predecessors. Styling is altered, but interior dimensions change little. Convertibles have a fully automatic power top and roll bars in the rear headrests designed to pop up if sensors detect an impending rollover. Tires are wider at the rear than at the front. Seventeen-inch wheels are standard on V8 models and optional on CLK320s in place of 16s. CLK55s have a sport suspension. CLK500 convertibles have exclusive AMG-designed trim. Mercedes' TeleAid assistance is standard. Options include Mercedes' COMAND video-screen control for audio and available navigation and phone systems. Also available is rear-obstacle detection, Mercedes' Distronic cruise control to maintain a set following distance, and its Keyless Go credit-card-sized transmitter to work locks and ignition by touch.