(FORTUNE Magazine) – Perhaps you'll think me cruel, although I was only trying to be kind. Usually I write about cars far in advance of their on-sale date so that you get the earliest possible glimpse--hear the engine, smell the leather, feel the acceleration--of the best cars coming on the market. But when I drove BMW's new M5, I thought that it was better to wait to tell you how sublime and significant a car it is until you could immediately run to the nearest dealer for a test drive. After all, the M-wizards in Munich have once again achieved the impossible--a neat hybrid that crosses a track-ready sports car with a luxury sedan and doesn't compromise either. Then they improved it some more. Woof. And so, while the new M5 is in fact arriving at dealers as you read, the U.S.'s allotment of 1,000 cars for model year 2000 is already spoken for. Remind me not to do you any more favors in the future.

Still, in the hope that a few idiots will suddenly question spending $69,970 on one of the best all-round performance sedans of the decade, I'll tell you exactly why I think it's so good. The reasons go beyond the M5's five-liter, 400-horsepower V-8 (the Ferrari 456M tops it with 436 horses) and its 369 foot-pounds of torque at a low 3,800 rpm (the Mercedes E55 pumps out 391 foot-pounds at 3,000 rpm). These days lots and lots of excellent high-performance cars are built, but this one is more than the sum of its parts. The M5 manages to blend an array of attributes into one tasty power cocktail.

Needless to say, I took my first sip in Germany. I found my Imola-red M5 tucked inside a garage at BMW, slid into the va-va-voom red-and-black leather interior, and fired her up. You just couldn't be prepared for the knock-you-back bass of the engine--it sounded like James Earl Jones bellowing. Other touches were equally alluring: Brushed aluminum accents the shifter knob, dash, and doors. A variable tachometer increases the rev limit as the oil temperature heats up, and an interior light beams through the double-H pattern on the shifter in the dark. Special enlarged front air dam, quad exhaust, xenon lights, tinted windows--when BMW makes a showcase vehicle, every detail exudes adrenaline. And all that was only skin-deep.... "Sue, can we go now?" my photographer, Angus, urged gently from the passenger seat. We were still in the garage.

I could tell you about our long haul on the Autobahn, in which everything that looked good worked even better. (After several hours at 135 mph, Angus couldn't help himself. "It's like a bloody TGV!" he gushed. "I mean, it's incredibly fast and really luxurious, isn't it?" Thank you, Angus. I couldn't have said it better myself.) I'd rather, however, tell you about the real point of the pilgrimage: driving the Nurburgring, the most famous open-to-the-public racetrack on the planet. For years and years I've heard the tales of the track's 12 miles of sweeping, essing, banked, striped-curb splendor. Uphill, downhill, left, right you race, alongside every manner of vehicle--motorcycles, racecars, jalopies. Over every rise and through every curve, you can imagine the likes of Stirling Moss, Juan Manuel Fangio, and Luigi Chinetti flattening the accelerators in Aston Martins, Lancias, Ferraris. Today at the Old Ring (as opposed to the newer Formula One circuit nearby), about the only rule is the $9 you must fork over per lap. In other words, you pay, you play. No flagmen in corners, no insurance forms, no licensing requirements, and (gulp) no helmet required.

Judging by the stares I got from the hardcore motorheads in the parking lot, the M5 was earning me a lot of respect. I marched into the ticket office, purchased ten laps, and strapped in. A magnetic ticket reader and tollgate arm permitted me access--and I was off.

There was one word for my first lap: dizzying. With the traction control shut off, the M5 handled itself like a tight little sports car; I forgot I was in a soccer-mom-sized sedan. It gripped hard around sweeping turns, the rev limiter glowing and the engine screaming toward its 7,000 rpm redline. It accelerated before my neck caught up on the straights, and braked more aggressively than I had any right to expect in the tight parts (and there are many). Through it all, the transmission was flawless, the gears smooth, the steering quick, the body stiff and roll-free. I experienced that moment, rare even in an expensive machine, when you realize the car can anticipate your every move and need--mind meld. One lap, for kicks, I kept up with a Yamaha R1 for a few turns (a motorcycle that's capable of zero to 60 in 1.3 seconds) before it pulled away. The next lap, I blew past an old M3 and duked it out with a 911 Turbo. More than 120 racing miles later, I staggered out, wishing my concentration could keep up with the M5's prowess. I spent that night at the Hotel Dorint, a shrine to motor sports, and awoke the next morning to the sound of GT3 cars testing. My nirvana--although for a daily driver, the M5 is my pick.

Of course, even gods have flaws. In the M5's case, her name is Helga (actually, I had originally dubbed her Olga, until her personality prompted the switch). Helga is the calm, vaguely breathy voice attached to BMW's excellent--the best I've used--onboard navigation system. At first I was impressed by her accuracy, amused by her willfully calm tone. Then we hit bad traffic. I asked Helga for a new route, and she obliged, but her precise commands grew vague. "Left in 50 meters," she'd say, as we came up to a six-way intersection. So I yelled at her a few times. "You're being a little hard on her, aren't you?" asked Angus. "How can you have a crush on a computer?!" I snapped. We didn't speak for a while, but we got there.

The only other defect I could find was the cell phone, which was placed perfectly in line with my right elbow. Otherwise, dear reader, hurry. Someone may be backing out of a down payment. And if you take my advice on both counts and go to the Nurburgring, check out the Cockpit, the Hotel Dorint's history-laden bar. Find a free spot on the wall and add your autograph alongside all the other drivers'; after the Ring, you've earned it. Just don't try to squeeze above Michael Schumacher's scrawl--I already did.