The most famous Mercedes-Benz is arguably the race-car-derived 1954-57 300SL coupe, with upward-opening doors that gave it the nickname "Gullwing" and a road car's first fuel-injection system. Good ones are valued at $595,000 -- and up.

It's thus not surprising that Mercedes put 300SL Gullwing features on its facelifted 2009 SL550, which is a rock-solid convertible with a snug, retractable hard top that can be opened or closed in 16 seconds.

The "retros" include twin power domes (thin, lengthy bulges) on the hood and louvers on front fenders. They make the stylish, prestigious two-seater look more rakish than the 2008 model. The $95,900 SL550 also has a new single-bar grille reminiscent of the Gullwing's and more angular headlights -- besides new 18-inch five-spoke wheels.

The rear has a pronounced diffuser, which resembles a spoiler, and trapezoidal tailpipes that look cool and emphasize the car's width. There's also body styling from Mercedes' high-performance AMG division to enhance the aggressive styling, although the low front end can be damaged unless you're careful when pulling up to concrete parking lot barriers.

Interior updates include a three-spoke steering wheel, with easily used shift paddles if a driver doesn't want to just leave the automatic transmission in its responsive "drive" mode, and a modified instrument cluster that's easily read at a glance with eye-catching red speedometer and tachometer needles.

I drove a friend's show-condition 1954 300SL Gullwing on rural roads during a blistering summer day and found the car had an upscale-but-no-nonsense interior that was noisy (little sound insulation) and incredibly hot (no roll-down windows or air conditioning). The car was moderately fast by today's standards with its 3-liter, 240-horsepower inline six-cylinder engine. The reported top speed was 150 mph-plus with the right gearing, but most Gullwings topped out at about 130 mph.

The race-style tubular space frame called for climbing over high, wide door sills when getting in and out under the easily used flip-up doors. But steering, shifting, handling (despite heavy non-power steering at low speeds) and the ride were impressive. The 300SL won many races partly because it was very strong. Everyone -- then and now -- stared at the car, wondering who built it. (Only 1,400 were made.)

The SL550 is in a line of 2009 SL-Class models that have higher prices and are for power junkies. Besides the 382-horsepower SL550, they are the $136,100 V-12-powered SL600 (510 horsepower), $132,000 SL63 AMG (518 horsepower) with a new multiclutch transmission and over-the-top $190,700 turbocharged V-12 SL65 AMG (604 horsepower).

All are well equipped with luxury-car comfort, convenience and safety features. The SL550 for instance, has the world's first automated roll bar, locking in place in a third of a second if sensors detect an impending rollover.

New standard equipment includes a large Panorama roof and a Parktronic system to prevent sheet metal damage in close quarters. There's also a new head unit with hard drive navigation, SD memory card reader and iPod integration. New Palladium Silver paint especially sets off the sporty styling.

Optional for the SL550 is Airscarf -- a heating system built into the seats. It lets warm air flow from vents in the head restraints, acting as an invisible scarf around the head and neck to allow comfortable top-down driving in cooler months.

The SL550, with all its power and a whopping 391 pound-feet of torque fed through the seven-speed automatic transmission, provides strong, linear acceleration from any speed, doing 0-60 mph in 5.3 seconds. The manual-shift feature, controlled by the steering wheel paddles, allows quick shifts but doesn't really seem necessary.

Fuel economy isn't a strong point of the fairly large, 4,220-pound car, at an estimated 13 mpg in the city and 21 on highways. Premium fuel is recommended, and the car has a $1,300 gas guzzler tax.

The nicely geared steering feels natural, with the right amount of power assist. The SL550 has an all-independent suspension that provides a smooth, supple ride, although some sharp expressway bumps can be felt.

The SL550 may fool one into thinking it's mostly a costly, upscale cruiser, but it has athletic handling -- enhanced by ultra-wide tires and Mercedes' Active Body Control system, which virtually eliminates body sway in cornering, squat under acceleration and dive during braking. Powerful ventilated, anti-lock brakes provide quick, sure stops, controlled by a linear-action pedal.

The SL550 isn't nearly as hard to enter or leave as the 300SL Gullwing. But long doors and a low-slung body create a "drop-in/climb out" interior. The luxurious cockpit has items such as leather and hand-polished wood trim. Front seats provide good support, but sound system and climate controls are rather small.

The retractable hard top takes up considerable space when lowered in the nicely shaped trunk. Trunk space is 10.2 cubic feet with the top up and 7.2 cubic feet -- or enough for two small golf bags -- when down.

The hood glides up on struts and the sophisticated engine looks huge under its big plastic cover.

While always costly, Mercedes SL-Class models have had good resale value. The SL550 looks a little less conservative than previous entry SL models, but still radiates understated affluence.