The CLS 55 AMG is one of Mercedes top performance sedans. It's performance stats have been questioned by some players as they do not seem to reflect what the car can actually do, leading them to believe they are incorrect and actually higher than stated.
As with most Luxury Sedans, it's sheer weight means it can't be knocked about easily and it's performance makes it one of the best choices of the B-Class, however as with all AMGs, it's performance cannot be upgraded beyond additional Nitrous. The car possess some longevity and holds it's own even after Level 1 Performance Parts for Class B vehicles have been shipped to the garage. However, by the time Level 2 performance parts for Class B vehicles are shipped to the garage, it may feel outclassed as typical opposition comprises of low-level Class A vehicles, which it cannot quite compete with.
The CLS 55 AMG can be purchased when Class B Vehicles have been shipped to the garage.