On Ocean Avenue in Carmel-By-The-Sea - that exclusive seaside enclave on California's Monterey Peninsula where the super-rich denizens drive mega-bucks cars with labels like Bentley, Aston Martin and Ferrari - we notice that more than a few of the sidewalk shoppers pay unusual attention to our vehicle with their heads turning and fingers pointing as we roll by.

What these spectators observe is a new kind of Mercedes that resembles no other vehicle in extensive Benz fleet.

It's large - stretching longer than the biggest full-size sedan and equally wide. It's bold in style, with a windswept face where the prow and windshield forge a raked plane sweeping up from front fascia and over a roll-top roofline. It has lots of doors. There's a pair of portals on each flank below what looks like one extremely long and narrow window stretching from the windshield clear back to the tail. Also, a top-hinged liftgate at the rear swings high for cargo bay access.

The profile vaguely resembles one of those big American mid-century station wagons, although the stance of this contemporary car seems to hunker on the pavement like a sports car and the beltline atop side doors rises like the raked face from a low point at the windshield to a high point in the rear corner.

Inside, there are three tiers of seats with a pair of individual buckets set in rows one and two and three. This is a first-class cabin, as appropriate for a Mercedes, with leather covering seats and appointments of the quality and caliber of a deluxe full-size luxury car. And overhead there's the optional panoramic sunroof with two large glass panels consuming most of the ceiling space stretching front to rear above the cabin.

The overriding concept behind this design seems to merge attributes of the station wagon, a minivan and SUV with a luxury-lined limousine. Germany's Mercedes-Benz constructs this new vehicle at its American assembly plant in Vance, Ala., as a 2006 model under the R Class label.

Consider it a new crossover vehicle - the platform comes from the mid-size M Class of sport-utility vehicles and the body resembles a low-slammed station wagon or an elongated SUV but the function combines traits of the wagon, sport-ute and limo-like sedan.

Mercedes even coined a new category for R Class cars -- Sport Tourer. The sport end of the title stems from performance characteristics and the driving manners of a tautly-tuned sports sedan. The tourer title comes from the European tradition of calling a wagon-type vehicle the touring model.

End result becomes a vehicle with practical attributes of a wagon but the fun-to-drive nature of a sports sedan and the refined cabin of a Mercedes big-class luxury car.

These two 2006 wagons -- R350 and R500 -- drive and ride like plush luxury Mercedes sedans and they feel as comfortable. Yet they also provide a surprising amount of cargo space in the back bay and can carry up to six people in first-class comfort in a vehicle with the sticky tire traction of a pavement-hugging all-wheel-drive (AWD) SUV.

Nomenclature for all Mercedes vehicles consists of alphanumeric designations, with the class size defined by alphabetical letters and the engine volume expressed in liters and translated into three digits. Thus, for these new wagons the R350 takes its name from the R Class of six-seat stretched wagons and its 3.5-liter V6 engine turns into the numbers 350. Likewise with R500, which packs a 5.0-liter V8.

The V6 - a new-generation engine with twin cams on top and variable valve timing - produces 268 hp at 6000 rpm plus 258 lb-ft of torque peaking between 2400 and 5000 rpm. The V8 runs up to 302 hp at 5600 rpm with 339 lb-ft of torque.

Transmission employed with either plant is the impressive Mercedes 7G-tronic TouchShift automatic -- first seven-speed automatic transmission for production cars that pops up this year in many different Mercedes classes.

The 7G-tronic operates with a stubby stalk protruding from the right side of the steering column. To select a gear, you raise the stalk one notch for reverse, lower it one click down for drive or depress a button on the stalk's cap to park.

While driving, you may leave the stalk in full automatic mode or play the TouchShift buttons -- positioned on the back side of the steering wheel's cross bar -- to switch gears. To-and-fro movements of the TouchShift buttons step up or down the gear ladder one notch at a time with the control of a manual stick.

The full-time AWD device for both R Class cars uses three open differentials -- front, rear and center. The center differential controls wheel speed up front and enables the forward rollers to turn at a faster rate than the rear ones during turning maneuvers. Likewise, the fore and aft differentials allow outboard wheels to spin faster than inboard wheels in a curve.

Then Mercedes adds a four-wheel adaptation of the electronic traction control system dubbed 4ETS. Wheel sensors determine when a single wheel may slip on a slick surface and the device then brakes the slipping wheel and transfers engine torque to the other wheels to maintain forward progress.

Also aboard is the alphabet soup of computerized vehicle controls -- anti-lock brake system (ABS) with brake assist (BA), and electronic stability control (ESP). And Mercedes provides roll-over sensors, curtain-style air bags for all tiers of seats, and a tire pressure monitoring system (TPMS).

A height-adjustable Airmatic air suspension system with active damping system (ADS) is on the list of optional equipment, which also shows a rear seat video entertainment system, Harman/Kardon Logic 7 audio system with six-disc CD changer, triple-zone interior climate controls, the panorama glass sunroof with pop-out rear-quarter windows, a power liftgate, Keyless Go entry device, Parktronic distance sensors, bi-xenon curve-illuminating headlamps, and a DVD-based navigation system plus satellite radio service via the Sirius network.

And the bottom line: It begins at $48,775 for the R350 and $56,275 for R500.