Boston.com's view

This is the story of a carrot, a stick, and a car.

The carrot: sporting elegance imbued with almost 400 horsepower and an active suspension system that devours lateral force.

The stick: a $1,700 gas-guzzler tax. But if you can afford $100,000 for your ride, this stick might be more of a twig.

The car: the 2007 Mercedes-Benz SL550 roadster.

In its 50th year of producing the classic SL class, Mercedes has added a 32-valve, V-8 engine (from its big S-Class cars) to this convertible model, bumping its horsepower from 302 to 382.

Just as significantly, it has mated the engine to a seven-speed automatic transmission that adapts so seamlessly to your driving style that the manual option is unnecessary.

The result of all this — combined with sleek lines that somehow say 2007 and 1957 simultaneously — is a car that might remind you of those late-night commercials that proclaim, “But it’s not just a . . . it’s also a . . . and wait, there’s more . . .”

Consider that this 2-ton-plus vehicle can rumble slowly and softly on city streets. But hit the highway or twisting back roads and it suddenly feels light and powerful.

The shifter is virtually invisible in its operation if you drive with moderation. Cruise and it works its way up and down the seven gears like a piano savant tickling the keys. Push it hard, and it becomes a different transmission, holding gears through the ascending rpms of rapid acceleration, refusing to upshift from your lowest gear of choice as you exit a corner in hot fashion.

Active body control suspension is another facet of the SL550’s “wait, there’s more” personality. Do the slow urban crawl and it remains soft for gentle cornering or the absorption of city street imperfections. It’s also like that in steady highway cruising.

But drive the SL550 hard and it stiffens up (60 percent stiffer than the SL500), eating those G-forces so that what you feel is not translated into a desire on the part of your cranium to move into the next seat — with or without the rest of your body.

The steel top goes up or down with the touch of a button — and in just 16 seconds. Top down, windows up, it is very quiet. Significantly, there is virtually none of the cowl shake usually associated with a drop – top.

The interior features sumptuous, stitched leather (even on dashboard seams), elegant wood, a big cockpit feel, and firm, gripping seats.

Standard safety equipment includes electronic stability control, traction control, antilock brake system, front and side air bags, the automatic body control suspension, and pop-up roll bars behind the seats.

The $95,000 base price of our test car added $510 for an electronic trunk closer and $3,150 for a premium package that added ventilated seats with multifunction contouring, Xenon headlamps, fog lamps that “see” around corners, and keyless starting. Toss in $900 for a wood and leather wheel and shift knob, plus the $2,100 or so extra for all the gas you’ll consume at 15.4 miles per gallon, and you’re topping $102,000.

For those with the money, though, this is a superior sports car. And if that’s not enough, climb on up to the SL600 (priced at more than $130,000), the SL55 AMG (about $130,000), or the SL65 AMG, whose 604 horsepower comes with a price tag of almost $300 per pony — $186,000.

Sure, most of us will never be able to afford cars like these, but it’s fun to travel in their rarefied atmosphere occasionally.

Royal Ford can be reached at ford@globe.com.