You already know that men will never stop to ask directions. Well, the dirty little secret of car reviewers is that we feel the same way about owner's manuals. Trial and error, that's our motto. If we can't figure out what a button is for, push it and see what happens.

But there I was, sitting in the driver's seat of a 1998 Mercedes-Benz E320 wagon, "key" in hand, and I couldn't figure out how to start the thing.There was a circle on the dashboard that looked like the place where the ignition key should go, but it seemed more like something you'd plug a toaster into than a key slot.

In my hand was one of those black plastic doohickeys that have become ubiquitous with new cars; in addition to holding the key, they have buttons that lock and unlock the doors as well as a "panic" button that sets the lights flashing and the horn honking.

The gizmo had those, all right, but where was the key? Past Mercedes key-fobs have had a button that flips the key out like a switchblade knife. This one did not.

I had to make a quick decision: I could make a fool of myself by hailing down the guy who had just delivered the test car and was about to drive away in the Volvo I had earlier reviewed, or I could (shudder) open the glove compartment and read the owner's manual.

I chose the fool scenario and leaped from the car, waving frantically at the delivery guy as he was about to pull out into traffic. Where's the key? I ask as he rolls down the window. I gave it to you, he says. No, I say, you gave me this plastic thingy. That's the key, he says. How so, I say. You just plug it into the dash, he says . . . like a toaster.

Oh.

Mercedes calls it SmartKey, and it's the world's first fully electronic key system. The idea is that there's no key for a thief to illegally copy, thus no way to unlock the steering or start the engine without the owner's remote unit.

This unkey sends an infrared data signal to an onboard computer, which then asks it for a pass code. If it gets the right one, it lets you drive the car. If it doesn't, it doesn't. And the code changes every time the car is started.

Isn't progress grand? And it can be yours for only $55,955, plus a big tax hit and a hefty insurance bill.

Oops, I wasn't going to talk about the price of this car quite so soon. I was going to tell you all about its wonders and then sneak the sticker shock in at the end. Sort of, "Oh, by the way. . . . "

But what the heck. You already know that Mercedes-Benzi are made for people in the upper tax brackets. What, you want Mr. CEO to drive a Yugo? Rich people have to have pricey cars so that you can tell them apart from people like me.

Sure, we're all stuck in the same traffic jams out there - the I-15 contractors don't play favorites - but Mr. CEO's stuck in a Mercedes, with a burled walnut dash, a Bose premium CD sound system, saddle leather seats, xenon headlamps and power everything - including the headrests.

And just so we don't confuse the Benz with a loaded Chevy Malibu, or something, the Mercedes has some doodads that stretch the boundaries of what defines a luxury car. For example, the "rain sensor" option regulates wiper speed according tohow fast the rain is falling, while "Parktronic" can detect unseen tricycles, curbs and shrubs (maybe even children) fore and aft and warn the driver with visual and audible signals.

Is the E320 worth the price? Probably not in the strictest value sense. The Volvo Cross Country wagon had all of the bells, whistles and safety features that most people could ever want in a car and it was priced nearly $20,000 less than the Benz.

Also, the Volvo's five-cylinder engine with turbo booster seemed just as powerful as the 320's V6. (You have to move up into the "S" class before a V8 becomes an optional powerplant. The Mercedes pecking order is ruthless.)

But let's face it, Volvo does not have the same status quotient as Mercedes-Benz. If you want that three-pointed star on your hood - arguably the world's most prestigious automotive icon - you have to pay and pay big. The law of diminishing returns has never been more evident.

(Before you send me letters telling me that Rolls-Royce's Flying Lady hood ornament carries more status than the Mercedes star, you should know that the automotive press considers the R-R, price notwithstanding, unfit to follow in M-B's tire tracks.)

Price aside, the Mercedes wagon has one clearly useful feature that is missing on the Volvo: A two-person, rear-facing, pull-up jump seat in the back that my wife and daughter declared to be not only comfy but entertaining - "Like riding on a train," they declared.

Using the jump seat eliminates the inside cargo space but luggage can go on the optional roof rack. In any case, it gives the wagon seating for seven people, the same as a minivan. However, truth in journalism mandates that I tell you the Ford Taurus wagon has the same jump seat feature in a vehicle costing less than half the price of the Benz.

Base price of the E320 wagon was $49,250. The leather seats were a $1,695 option; adjustable lumbar seat bolsters added $780; headlamp washer/wipers $340; xenon headlamps, which emit a very white light much like a flourescent, $960; luggage rack $390; heated front seats $595; sunroof and Bose sound system $1,350; destination and delivery $595 for a total of $55,955.

Popular wisdom has it that people who buy $56,000 cars don't care a fig about gas mileage, but I suspect that's wrong. In any case, the E320 gets a decent 20 mpg in city driving and 26 on the highway.

Bottom line: The M-B E320 is a really great car and probably the best station wagon money can buy, but it takes a whole lot of it.