The Good: Seven-speed automatic transmission with manual gear select; auxiliary jack for MP3 player; luxury interior; solid sound system. The Bad: Complicated navigation interface; Mercedes-Benz-brand cell phone integration; standard in-dash CD player not MP3 compatible. The Bottom Line: Beyond a few proprietary issues, the Mercedes-Benz ML350 offers better comfort and performance than most street-oriented SUVs. 2006 Mercedes-Benz ML350The 2006 Mercedes-Benz ML350 demonstrates how the once-conservative carmaker's lineup and styling is now geared toward younger and more American tastes. The second-generation ML350 debuts for 2006 with significant changes. Most obvious is the styling, which, while definitely M-Class Mercedes in shape, has been freshened in line with the company's other offerings. It's longer, wider, and roomier. But the most important change lies under the skin. The new ML350 has gone from trucklike body-on-frame construction to a carlike unibody structure for improved rigidity with less weight. While the ML 350's namesake 3.5-liter V-6 engine is the same size as last year's engine, it's entirely new, with 36 more horsepower and improved fuel economy. The transmission is now a seven-speed automatic, the first such in an SUV. As before, the suspension is fully independent, and a full-time, single-range four-wheel-drive system is standard equipment, aided for safety and ease of use by a range of sophisticated electronic-safety assistance systems. Our test vehicle provided the quiet comfort expected of a Mercedes-Benz luxury sedan, with the space and interior versatility of a midsize SUV. The base price is $39,750, but a $720 destination charge and $8,355 worth of options brought the MSRP up to $48,825. That's $690 for the Iridium Silver paint, $75 for the power folding mirrors, a reasonable $1,240 for the DVD-based navigation system, $500 for Sirius Satellite Radio (plus a monthly subscription fee), $490 for a trailer hitch, $690 for heated front seats, $2,200 for the Trim Package (leather seating surfaces and wood trim, privacy glass, roof rails, HomeLink, and TeleAid), $1,080 for the Entertainment Package (a Harman Kardon Logic 7 audio system and glove-box-mounted six-CD changer), and $1,390 for the Sunroof Package (power sunroof and rain-sensing wipers).The 2006 Mercedes-Benz ML350 is very much a contemporary Mercedes-Benz product inside. Stylistically, it's complex and visually busy, with many different shapes on the instrument panel, console, and doors. With the optional Trim Package, wood and aluminum accentuate the dashboard. Space is noticeably improved compared with the old M-Class, with 3 inches of extra width and 4 inches more wheelbase put to good use. The seats are firmly comfortable, with power-adjustable front buckets and a 60\/40 split flip-and-fold rear bench that allows a long load floor when utility calls. All the amenities expected in a luxury vehicle are onboard, including one-touch up and down windows all around and a very good dual-zone climate-control system with rear-console air and floor heat ducts. Road and wind noise are at the low levels expected in a luxury car.The Mercedes-Benz Command interface features 10 soft buttons, six hard function buttons, and a number pad.As in an increasing number of vehicles, there is no mechanical key. It uses the SmartKey device developed by Mercedes-Benz in the late 1990s. A search for the shift lever will, at first, come up blank. The usual spot on the console has two cup holders, bracketing a useful slot for a parking lot card or a bridge pass. The shifter is a deceptively small lever on the right side of the steering column behind the wheel. The top lever on the left is the traditional Mercedes-Benz cruise control, which is guaranteed to be mistaken for the turn-signal lever the first few times at the wheel.The LCD in the middle of the center stack shows Mercedes-Benz's Command interface, encompassing navigation, audio, and telephone functions. Menus are controlled by context-sensitive buttons to the sides of the screen, while acceptance of commands and navigation of the map display is done by a small joystick button. It also includes a number pad to the right, which is a nice touch. Unlike some other nav systems, no control functions appear accessible when you're in map display mode. To enable them, press any button, and they will be displayed for a short time, overlaying the map next to the appropriate control buttons. It takes some effort to get used to entering addresses and appreciating the little quirks of the nav system. Also, Mercedes-Benz has not adopted Bluetooth yet; the only way to get cell phone integration is to get a Mercedes-Benz cell phone, manufactured by Motorola, with the car.We were pleasantly surprised to find an auxiliary audio jack hidden in the glove box.Visibility is average, as is route-finding ability. The system not only calculates routes to various points of interest but also can tell if there is a nearby parking lot. Note that not all parking areas are in the database; however, an update service is available. Latitude, longitude, and elevation are displayed at the bottom of the map screen. There is also a compass display with that information, presumably useful off-road or at least out of the area covered by the map database.Looking for the CD slot? As has been the Mercedes custom for some time now, it's hidden behind the Command screen, as is the DVD-ROM slot for the navigation-system disc. And no, movies cannot be played in the nav-system DVD slot. The single-disc CD player is not MP3 compatible, though the optional glove-box-mounted changer is. There is an auxiliary input jack in the glove box for connecting an iPod or an MP3 player, and sound quality from the optional Harman Kardon Logic 7 audio system is very good. From the protruding matte-black perforated grille, prominently adorned with the Mercedes-Benz tristar emblem, to the squared-off taillights, the 2006 ML350's body looks familiar in shape and proportion but uses more sculpting on the front bumper fascia and around the wheel arches, as well as a strong, rising character line on each side. The windshield is more raked to an angle that would have been considered only for sports cars not long ago. Aerodynamics are good, with a coefficient drag of 0.34 compared with 0.40 of the first-generation M-Class. This improves fuel efficiency and reduces wind noise. Like a car, the 2006 Mercedes-Benz ML350 is made with true unibody construction, as opposed to the body-on-frame design of its forebear. This gives it a stronger, more rigid structure, which improves both handling and crash safety. The suspension is completely new, with double wishbones in front and a four-link system in the rear. On smooth or gently undulating surfaces, ride quality is solid. The springs and shocks are tuned fairly softly for comfort but with good damping and control. The unsprung weight of the large, heavy wheels and tires makes itself known by some harshness over sharp disturbances such as expansion joints. Get used to the new Mercedes-Benz shifter, as it's becoming standard with the seven-speed automatic.Handling, as always with the M-Class, emphasizes the sport side of sport utility. The speed-sensitive power steering allows a light effort at parking speeds, with more effort at highway speeds for control. As in other SUVs, the high seating position means good visibility but also amplifies body roll. An air-suspension system is available, which includes adjustable ride height and variable, adaptive shock damping. The 2006 Mercedes-Benz ML350's 3.5-liter V-6 engine shares only its displacement with the engine used previously. In place of the old engine's single overhead camshaft per bank and three valves per cylinder are dual overhead cams and four valves per cylinder. Variable cam phasing works on both intake and exhaust cams to improve power characteristics and decrease emissions. Electropneumatically driven, electronically controlled tumble flaps in each intake duct improve airflow for lower fuel consumption and emissions. Power output is higher than the old engine's, with 268 horsepower at 6,000rpm and 258 pound-feet of torque between 2,400rpm and 5,000rpm. Even better, it's smooth, quiet, and linear. When driving the ML350, we never wished for the ML500 V-8 version. Zero-to-60 time is quoted by the factory at 8.4 seconds--better than some competitive V-8 SUVs.This type of power and acceleration is helped significantly by the 7G-Tronic seven-speed, electronically controlled automatic transmission. With close-ratio gears, it is almost as seamless as a CVT. Both sixth and seventh gears are overdrives, offering improved highway fuel economy. EPA ratings are 16mpg in the city and 20mpg on the highway. We averaged 17mpg.Shifting the steering-column-mounted stalk is a little strange at first, as there is no mechanical feedback. Reverse is up, neutral is center, and drive is down, with intermediate gears manually selectable via rocker switches on the back of the steering wheel's spokes--you can downshift by pressing the forward end and upshift by pressing the rear. Because of the engine's wide torque band and the transmission's adaptive shift logic, manual shifting is an entertaining option, not a necessity.The full-time four-wheel-drive system splits torque evenly between the front and rear axles in most conditions. The 4ETS electronic traction-control system helps control torque distribution to each wheel, and the engine, transmission, and antilock brake systems communicate with it for optimal traction control on or off pavement. Downhill Speed Regulation and Hill-Start Assist systems aid low-speed maneuvering on steep grades, particularly in loose conditions.Most safety systems taken for granted today are Mercedes-Benz innovations, and the 2006 Mercedes-Benz ML350 is equipped with the full complement. Like a passenger car, it has a strong safety cell around the passenger compartment, front and rear crumple zones, and side protection. The brakes are four-wheel discs, and the antilock system has an off-road mode. All seating positions have three-point safety belts, and front dual-stage, front-side, and front and rear side-window air bags are standard. Front air-bag and seat-belt force-limiter strength adapt to the force of an impact. The ESP electronically controlled stability-control system is standard, as is the Pre-Safe anticipatory occupant-protection system, which integrates all electronically controlled safety equipment to prepare for a possible impact when the ABS, Brake Assist, or ESP systems so indicate. The TeleAid telematics and emergency communication system is part of the Trim Package. The warranty covers defects in materials and craftsmanship for four years\/50,000 miles, with 24-hour roadside assistance.