The S-Class returns for 2005 available in four engine trims: the 4.3L V-8 S430, the 302-hp 5.0L V-8 S500, the 5.5L Supercharged V-8 S55 AMG, and the 5.5L twin-turbocharged V-12 S600, boasting 493 horsepower. Standard amenities across the board include premium leather seats, polished wood interior trim, an in-dash GPS navigation system, and Airmatic air suspension. Higher trim-levels add upgrades such as Nappa leather seats, heated front sport seats, Active Body Control suspension, chrome exhaust tips, and four-zone climate control. Unique options available on the S-Class include the Parktronic parking aid system, Keyless Go, a voice activated portable telephone, and Distronic cruise control.