(FORTUNE Magazine) – WARNING: INDEFENSIBLE DECADENCE AHEAD. PROCEED WITH CAUTION.

This month I dally not with an ordinary automobile, but with a supercar, the 1997 Lamborghini Diablo Roadster VT. A vehicle so exotic, so bespoke, so feral, so costly, that normal comparisons of economy and performance are moot. Diablo is to car what Hope is to diamond, or Pavarotti to humming in the shower. I'm not even sure it's a car at all--plane, rocket, sculpture, endangered species may come closer.

Not many companies make supercars. Some of the names you've heard whispered reverently--McLaren F1, Ferrari F50, Jaguar XJ220--but you've probably not run into many on the street. They all make four years of college with room and board look cheap, and the Lamborghini is no exception. It costs $249,000--before luxury and gas-guzzler taxes. So while my normally nonchalant pulse rate jumped when Lamborghini invited me to be the first American writer to drive the 1997 5.7-liter V-12, 492-horsepower Diablo on U.S. pavement, I had my doubts about reviewing any four-wheel entity that cost so much dough. Even though the company crafts only 225 a year, is it really art, or just excess?

Lamborghini headquarters in Jacksonville also gave me pause: It's a low-slung, modern building, more cookie cutter than Medici palace, more industrial park than Florentine piazza. I began to wonder whether the Diablo, which crouches in the garages of Donald Trump, Mike Tyson, Nicholas Cage, and the Sultan of Brunei (he owns several), was really just so much soulless flash.

Happily, Italian authenticity waited just around the corner. Cosimo Nasole--everyone calls him Mimmo--is Lamborghini's chief U.S. test driver, national service manager, and occasional technician to the Sultan (the guy's got a car collection in the neighborhood of 1,750 vehicles, so he needs a lot of help). He took over as my guide. As he began introducing me to the vehicle--its shape at rest looking exactly like speed blur--his hands danced. "This car could not be made without the passion of the workers," he insisted in thickly accented English. "Every piece is made by hand--crankshafts, camshafts, dashboard--by people who have spent their whole life doing this and nothing else." My mind's eye saw a cathedral-ceilinged, frescoed factory filled with men and women toiling over intricate parts, endless coats of paint, and buttery pelts of leather, while dark-haired sopranos sang arias from a balcony.

Mimmo and I wriggled in past the saluting gullwing doors, and while I groped for the handle, he fired up the engine and shot out of Lamborghini's vast and immaculate garage. He slammed the car sideways through the parking lot; as we slid, I spied tire dust off the 17-inch wheels swirling across the road behind us. A split second later, he straightened the Diablo out with a snap and hammered ahead. No swaying, no rolling, no hesitation, just unadulterated energy. It was an all-sensory extravaganza.

As he drove, Mimmo explained that every year he has to teach several new owners how to handle a stick shift. I was horrified, but he responded, "It's not so crazy as an Italian company being owned by an Indonesian--but he pays the bills." True enough. In an impressive high-performance deal in February 1994, Tommy Suharto, the youngest son of Indonesia's leader, president Suharto, bought the Italian company from Chrysler, as well as an interest in the ever-failing American supercar project, Vector (also housed in Jacksonville).

Turning from politics, we came to a deserted patch, and he flicked the car into a 360-degree spin, then roared off, glancing to see my reaction. "I know this car like it's my body," said Mimmo, shifting into fifth gear so I could hear him over the operatic engine.

Finally, my turn. As we switched sides, I paused to admire the Diablo's razor-sharp lines. Suddenly, I felt a tug on my jacket--the yawning air intakes behind the doorframe were inhaling the fabric. Walking behind it, I was surprised by the force of the blast from the exhaust. That's when it occurred to me that the Lamborghini was the most alive--and ominous--vehicle I have ever encountered.

The sensation continued inside: strapped into the racer-snug seat, I felt the car's power all around. (Welcome to Imax Theater. Please put on your 3-D headsets now.) Behind me, the engine purred into my ear; under me, it vibrated restlessly, straining to leap ahead. Even the steering wheel transmitted the raw timpani of 48 valves. Time to go, time to go, time to go. Guiding the shifter into first (a metal gate prevents any mis-shifts), I let out the clutch and unleashed the beast. The instantaneous g-force was unbelievable. Within a few blocks, I looked down: 100 mph in third gear. Suddenly I understood its name: I was lap-dancing with the devil.

As I grew more comfortable at the controls, the car's outrageousness faded, and I began to appreciate its civilized elegance--it was letting me have my way with it, but it wasn't going to let me lose my head. I decided to test its good breeding and claimed acceleration of zero to 60 in four seconds. I guess I got a little carried away, because a few ticks later, Mimmo yelled over the roar, "I don't know what police do for 120 miles per hour, but I like you appreciate the car." You only live once.

At the end of the day, I reluctantly climbed out. Don't get me wrong. I will not in this lifetime spend a quarter-million dollars on a car, and I'm not suggesting you should either. Unless--as the saying goes--money is truly no object. This is a car to rough up lovingly, not tiptoe around. The Diablo, though a vast improvement over its hard-to-handle predecessor the Countach, is by no means perfect: It took two people to handle the 12-pound targa roof; the windshield kept steaming up, and visibility out the back was nothing to speak of--literally. I won't even get into repair bills. But that's not the point. In the end, the Diablo is a piece of art. As for more commercial equations, Is its leather that much softer than Aston Martin's? Its engine that much more muscular than Porsche's? Its styling that much more unique than Ferrari's? Maybe, maybe not, but Lamborghini does offer a wildly in-your-face, limited-edition blend of 19th-century craft and 21st-century technology. It comes from--and transports its driver to--another world entirely. God forbid I put a price on such a thing.