2003 Mercedes-Benz SL55 AMG

Few racetracks in the world elicit such praise and respect as does Road America. Get it right, and you've conquered the hairy beast. Get it wrong, and it will eat you up.

Road America's high-speed straights and challenging corners are an extreme test of a car's skills and a driver's mettle, so it would seem the perfect venue for a first drive of the new SL55 AMG. It's the fastest production car yet from Mercedes-Benz, and the 493-bhp supercharged V8 is the most powerful production engine that's ever lurked behind a three-pointed star. World-class machinery on a legendary track. Could it get any better than that?

No, but it could get worse. Add pavement-slicking rain showers to the mix, and what was an exciting opportunity could turn into an expensive pratfall-or worse. I'd already driven AMG-tweaked Benzes on a track in the rain, a couple of years ago at Hockenheimring, and the memory of sliding the muscular, expensive cars around a slick circuit had my imagination hurtling down a slippery slope of ugly scenarios. I also had memories of driving Road America in the rain, which did nothing to inspire my confidence, waning along with the evening light.

Still, I'd also had a lot of fun on Road America when it didn't rain, and I hadn't crashed anything that damp day at Hockenheim, so my expectations were mixed. In the Mercedes camp, the tension seemed thick as the clouds looming over the track (What does a fender cost on a $124,000 car?), but we journalists just chattered away like a bunch of monkeys. For a moment I imagined we were part of a mad experiment ("If these apes can drive the car here, in the rain, without bouncing off the walls, we've built the perfect sports car."). But then the roar of a blown V8 dopplering down the track's long front straight dissolved the fantasy, setting off a Pavlovian response to the sound of high revs and horsepower. Grabbing a helmet, I was ready for my laps

Because of the weather, the retractable hardtop was deployed. Had I been gamboling down PCH in Malibu instead of lapping a wet track, the roof would have been stowed (it takes just 16 sec.), though at little compromise to my safety. As the SL is both a roadster and a coupe, it's been equipped with high-tech variations on accepted safety practice. An "active" rollover bar raises in just 0.3 sec. (whether the top is up or down) in cases of impending rollover, nothing new there, but now it's also activated when an acceleration sensor determines a "hazardous situation" is taking place, such as in front, rear or side impacts. A second safety consideration was side protection for the upper body and head, as the SL's folding roof doesn't allow side-curtain air-bags. Engineering solved the problem by designing a new door-panel-mounted "head-thorax" airbag that offers virtually as much upper-body protection as Mercedes' conventional setup.

Determined not to test those aspects of the systems-rich SL55, I braked early, treaded lightly on the throttle, and kept front straight speed well below the electronically limited 155 mph. And I also relied heavily on the car's arsenal of electronic traction-and braking-aids to stay almost nearly on line through the course's difficult corners.

As if the basic SL suspension weren't sophisticated enough-fully independent, with double A-arm front and five-link rear-the SL55 also offers the magic of Mercedes' active suspension system, ABC. Designed to eliminate body roll during cornering, braking and accelerating, its software in this application was rewritten for sportier handling, thus offering, states Mercedes, 68% more "stiffness" than a conventional suspension would deliver on the same car. For the track session at Road America, and for any time the driver wants the most control from ABC, a console-mounted switch allows a whopping 95% less roll than would be felt from a conventional suspension.