CAPETOWN, South Africa--In the Southern Hemisphere, sailors for centuries have used the constellation Crux, or Southern Cross, to guide their vessels across uncharted seas.

Modern-day explorers who are fortunate enough to have a new Bentley Arnage T at their disposal don't need to be professional stargazers. They can simply flip on the satellite navigation system to plan and execute a swift overland route.

Speed was hardly a priority on my first trip to the African continent, undertaken in mid-February to sample the newest British supercar from this boutique manufacturer, now owned by the Volkswagen AG Group.

Traversing more than 400 kilometers (about 250 miles) over two days, I must confess that I didn't rely once on the Bentley's navigation system. Fortunately, I had a fairly precise route book and the good company of three well-traveled companions, including two fellow Americans and an Australian.

Such a lengthy drive provided an intimate look at the new Arnage T, which goes on sale in North America in May, priced at a stratospheric $235,000. Curiously, our extended route through the mountains and wine country at the southern tip of Africa didn't reveal much in the way of wildlife. More on that later.

Our automotive safari began at the Grand Roche Hotel, an old Dutch-style manor house, now a five-star resort, nestled against Paarl Mountain about 30 kilometers from Capetown.

Once we realized just how roomy and sumptuous the Bentley's cabin is, the four of us elected to ride together for the duration. That way, we could take turns driving this high-performance, ultra-luxury sedan and being chauffeured in total elegance and comfort -- the motoring journalist's equivalent, I suppose, of covering the Super Bowl or the World Series from a luxury skybox.

Although they both claim VW as a common parent, sampling the Bentley from front seat and rear was definitely a far cry from piloting the family Beetle around the wilds of southeastern Michigan.

The last Bentley I'd driven was the fabulous Mulsanne Turbo some 20 years ago. It was late September in 1982, and I spent the better part of an autumn afternoon driving through the Welsh mountains in a steady drizzle, then back to the factory in Crewe in the British Midlands.

Now, two decades later, I had a rare opportunity to test the world's fastest, most powerful production sedan -- and the most potent roadgoing Bentley ever -- on similar roads, but in a warm and sunny setting at the other end of the globe.

Like most postwar Bentleys, including the Mulsanne, the Arnage is based heavily on a Rolls-Royce model -- in this case, the Silver Seraph.

The Arnage series was launched in 1998. The new Arnage T, which was unveiled in January at the Detroit Auto show, is the first of the so-called Series Two models that are being re-engineered from stem to stern in 2002. A slightly more sedate Arnage R will join the lineup later this year.

At the heart of the Arnage T is a reworked 6.75-liter V-8, now fitted with twin turbochargers. The engine develops 450 horsepower and 645 pounds-feet of torque -- enough to propel this 5,700-pound rocket from zero to 60 miles per hour in a deceptively quick 5.5 seconds. Top speed is electronically limited to 168 mph, which is fast enough to keep up with most big game.

I've driven plenty of big cars over the past 30 years -- remember those monster Cadillacs and Lincolns of the mid-Seventies? -- But none with quite the panache of the Arnage T.

Acceleration is virtually effortless, as power is transferred to the rear wheels through a modified General Motors 4L80-E four-speed automatic transmission. Upshifts are virtually imperceptible, while a convincing kickdown on full throttle is accompanied by a reassuringly smooth surge of power from that massive V-8.

The Arnage's all-independent suspension system features double wishbones at all four corners, with computer-controlled, multi-stage adaptive dampers providing a firm, albeit cushioned and controlled ride.

The car negotiates wet and slick surfaces with little fuss, thanks to the adaptation of electronic stability program, which helps prevent sliding or fishtailing. For extra grip, Bentley has fitted Pirelli P-Zero high-performance tires to 18-inch alloy wheels.

To protect occupants, the Arnage has front air bags, side air bags for front and rear passengers and full-length side air curtains.

What can I say about a cabin that looks like it was designed for royalty? While Bentley prides itself on being a "driver's car" (as opposed to Rolls-Royce's mostly chauffeur-driven clientele), the interior of the Arnage T reflects more than 80 years of hand-crafted heritage.

Seats are made of expensive, perforated Connolly leather, embroidered with the winged Bentley motif. The same rich hide is also used to line the roof. The instrument panel is trimmed in engine-turned aluminum, with tasteful splashes of burled wood here and there. Handles and switches are knurled for a more expensive look and feel. You can almost feel your feet sink into the thick Wilton carpets front and rear. And front and rear seats are heated and fully adjustable.

Who buys an exclusive vehicle like the Arnage T? Bentley executives say the typical buyer has a net worth -- never mind "median income" -- of $12 million. Bentley owners are a diverse group, ranging from actress-singer J. Lo to Prince Charles.

I'm not sure if any of them have had the pleasure of driving a Bentley this far below the Equator, where the Southern Cross still burns brightly in the summer sky (the seasons are reversed here) and the grapes will soon be ready for harvesting.

My only disappointment is that real-world Africa has failed to live up to the stereotype in some respects. The only "wildlife" we encounter during our sojourn is a barbecued springbok sirloin at dinner one night, followed by a grilled ostrich steak for lunch.

When I finally do spot a genuine ostrich at a watering hole the next day, I feel slightly queasy -- until I sink back into the Bentley's cushioned rear compartment for a brief post-prandial nap.

Home, James!

Bentley Arnage T

Wheelbase: 122.8 in.

Length: 212.8 in.

Width: 83.7 in.

Height: 59.7 in.

Curb Weight: 5,700 lbs.

Engine: Twin-turbo 6.75L V-8

Output: 450 hp

Where Built: Crewe, England

Estimated Price: $235,000

On Sale: May 2002