Commenters repeatedly note the CLK55 was the fastest/quickest production Mercedes sold in the US at its introduction, crediting its low ~3,400 lb curb weight and the big V8. Owners describe explosive, traction-breaking acceleration and a car that turns into a 'hard snorting beast' under throttle.
Straight-line performance and 'quickest Mercedes of its era'
Mercedes-Benz CLK55 AMG (C208) · driving