Now I know why rich people live longer. They have more air bags. The proof is in the 2000 Mercedes-Benz S500 sedan. Eight air bags. Eight! They include two front bags, four side bags (one in each door) and two curtain-type bags installed along the lower sections of the headliner on either side of the car. These aren't ordinary air bags. The two front bags are designed to deploy in stages, slowly in low-speed collisions and faster in higher-speed crashes. The idea is to avoid unnecessary bang, because too much bang is not a good thing, as evidenced by the unfortunate cases of people who have been killed or injured by the safety devices. The curtain-type bags help to protect heads and necks in side-impact crashes, and the door-mounted bags protect torsos in those hits. Sensors keep the four front bags from deploying if no one is sitting in front of them. That saves repair costs. But most folks don't buy cars to pop air bags. They buy to drive, which the S500 does exceedingly well. Imagine power so smooth, so evenly delivered, you must check the tachometer to make sure the engine is running. That's what you get with the 5-liter, 302-horsepower, aluminum-block V-8 installed in the S500. There is a 275-horsepower, 4.3-liter version of that engine in the 2000 S430. All of that power is beneath new sheet metal, including a good helping of aluminum in components such as the hood and deck lid. The new look--sleek, sporty, sexy, substantial--snaps necks big time. The use of lighter-weight building materials, including magnesium for certain engine parts, strips about 500 pounds from the new S500's weight. But not everyone was impressed. One dude in a dated Chrysler minivan used a red-light stop to shout, "It looks no better than a Ford Escort!" The ruffian! He would have had a different opinion had he sat in the car. He would've found supple Nappa leather seats, the front pair actively ventilated and powered to soothe backs and bottoms in myriad ways; burled-walnut accents in the S500 (eucalyptus accents in the S430); a Tele Aid system to get help in an emergency at the push of a red button; a screen-equipped Cockpit Management and Data System (Comand) that integrates the car's satellite-navigation, cellular-telephone and audio syst ems. And more, much more. In the end, he might have discovered an essential truth: Cars are more than a collection of components and fasteners that can be compared with other collections of components and fasteners. Cars have souls, personalities. Were that not the case, we'd all be driving generic metal boxes. The S500, by comparison, is a beautiful, expensive technological work of art. It speaks to the good life. I may not have the money to buy it, but I'm darned sure listening. 2000 Mercedes-Benz S500 Complaints: This sedan comes with another one of those all-things-to-all-people transmissions, a five-speed automatic (TouchShift) that can also be used as a manual. I'd prefer one or the other, manual or au tomatic. What do you think? E-mail me at email@example.com or write me at The Washington Post, 1150 15th St. NW, Washington, D.C. 20071. Praise: Nearly everything you want in a luxury car, if you can afford to pay for it. Ride, acceleration and handling: Superior on all counts in the big-sedan category. Cleans the clock of the even more expensive Rolls-Royce Silver Seraph. Superior stopping power. Brakes include power four-wheel discs augmented by anti-locks, traction control and electronic stability control. Head-turning quotient: Turned some faces green. Created palpable lust and some occasional outbursts of disdain. Test engine: Aluminum-block 5-liter V-8 producing 302 horsepower at 5,600 rpm and 339 pound-feet of torque between 2,700 and 4,250 rpm. Capacities: Seats five people, holds 15.4 cubic feet of cargo and carries 23.2 gallons of premium unleaded fuel. Mileage: About 19 miles per gallon, combined city and highway. Estimated 425-mile range on 23.2 gallons of fuel. Safety: In addition to multiple air bags and active safety devices such as traction control, the S500 has been constructed to crash with minimum destructive effect on an opposing vehicle and maximum protection for its own occupants. Price: Base price of the new S500 is $77,850. Dealer invoice on the base model is $72,400. Estimated price as tested is $87,705, including an estimated $4,485 in federal luxury taxes, a $1,000 federal gas-guzzler tax, $3,775 in options and a $595 destination charge. Purse-strings note: The S500 exists in a class by itself. Either you want it or you don't.