The car came with either 17-inch AMG monoblock wheels (said to be exclusive to the coupe) or optional two-piece staggered five-spoke wheels; the monoblocks are hard to find, while the two-piece design is easier to source and refinish. Owners note the AMG suspension geometry causes uneven tire wear and that the car goes through tires.
AMG monoblock versus two-piece wheels and uneven tire wear
Mercedes-Benz CLK55 AMG (C208) · cosmetic