As we dash under the Snap-On bridge, we enter the carousel. "You can carry a lot of speed into here," says Donohue. Who am I to argue with a pro like him? Especially since I haven't sensed any nervousness in his voice during our trip. And that's no small point. Ask any driving-school instructor--few things have the potential to scare the sweat out of you like riding in the passenger seat with some leadfoot you just met a few minutes ago.

But Donohue also has a backup in case of impending idiocy behind the wheel: Porsche Stability Management, which is standard instead of optional on the Anniversary Edition. The system uses the same basic throttle-and-brake-control principles employed by other manufacturers' stability control systems, but Porsche has programmed its system for enthusiast drivers. "It allows you to get a good feel of what the car is doing--understeering or oversteering--before it becomes active," says Donohue. "It'll only save you when you really need to be saved."

Indeed, as we press closer to the limits, the car remains pleasantly free of the lurching, nanny-ish intervention often exhibited by such systems in more prosaic cars.

2004 Porsche Boxster S 50th Anniversary Edition

The rest of the track plays out in a succession of elements that span almost the entire gamut of performance-driving conditions--a maddening, blind little chicane; another long, bent straightaway; and a series of medium-tight turns in succession. Through it all, the Boxster cooperates, shirt sleeves rolled up, eager for whatever you put it through.

It seems almost tailor-made for Road America. And that's saying a lot. Some lower-powered sports cars can feel lost--almost tediously slow--on this track's abundance of long, open sections. Conversely, high-powered, front-engine haulers often seem a tad clunky on Road America's tighter parts.

The Boxster is at home everywhere here. What's more, it's nimble enough to negotiate smaller, club-oriented tracks with equal aplomb, making it a worth considering for enthusiasts looking to get a good track-day car.

The Anniversary Edition Boxster starts at $59,900, which seems reasonable, considering that a comparably equipped regular Boxster S wouldn't be all that much less money. What's more, other Boxster models don't even offer some of the Anniversary Edition's features, including its lowered suspension, short-throw shifter, and unique silver paint.

As Donohue and I power through the last corner and ease onto the pit road, the din of the engine and wind dies down, leaving just a faint echo in my mind.