Although initially targeted for discontinuation by the end of the decade, the G-Class continues to roll on, thanks to its popularity with offroad enthusiasts and the fact that Mercedes-Benz maintains a number of long-term military contracts for the G-Class, which began its life essentially as a military vehicle. After receiving an update in 2007, which included a new transmission, steering wheel, instrument cluster, headlights, and taillights, the G-Class changes little for 2008. Nearing its 30th year in production, it still retains its straight-up, squarish retro design, as well as its extensive offroad capabilities and a long list of standard luxury-oriented features. Drivers can choose from two trims for 2008. The G500 comes equipped with a responsive 5.0-liter V8 engine that produces 292 horsepower. The engine links to a seven-speed automatic transmission that automatically adjusts shift points, depending on the driver's style. In addition, the driver can manually upshift or downshift by nudging the shift lever left or right. To ensure its offroad ruggedness, the G-Class includes a four-wheel-drive system with front, rear, and center locking differentials, all activated by the driver, making it one of only a few SUVs available with three locking differentials. A four-wheel Electronic Traction System and an Electronic Stability Program also come standard. Exterior features for the G500 include an electrically heated windshield, heated power mirrors, bi-xenon headlights with heated washers, and front and rear tow hooks. Inside, the G500 comes equipped with such features as leather seating, heated front seats, a heated wood-and-leather steering wheel, dual-zone climate control, Burl Walnut wood trim, and a DVD navigation system. Pumping up the power, the brawny G55 AMG adds a hand-built, supercharged 493-horsepower V8, as well as twin chrome sidepipes, a multicontour driver's seat, hand-polished "designo" wood trim, a Harmon/Kardon digital sound system, and a sport suspension and styling cues designed by AMG, Mercedes' in-house sport tuner.