Lorinser Tune just announced

The tuner is bridging the gap between the C450 and the C63 by infusing more power in the 3.0-liter twin-turbo V6. After applying its expertise, the motor was upgraded from 367 PS (267 kW) and 520 Nm (384 lb-ft) to 435 PS (320 kW) and 620 Nm (458 lb-ft) of torque.

The added punch costs €1,541 and has slashed 0.3 seconds from the 0-62 mph (0-100 km/h) task which now takes just 4.6 seconds. Lorinser didn’t fiddle around with the electronic top speed limiter, so the car still tops out at 155 mph (250 km/h).

More info can be found Here