If you’d have done such a thing back in school, your teacher would have rapped your knuckles with a ruler and pronounced you impertinent.

But here comes South Korean automaker Hyundai with a big, rear-drive premium sedan that the car company brazenly compares to Mercedes-Benz, BMW, Lexus…

Where’s that ruler?

Easy on the knuckles, though. Is the 2009 Hyundai Genesis a Lexus, BMW or M-B? Probably not. Does it matter much? Probably not.

Genesis is better than most people need, and easily good enough for most of the rest of us.

Genesis’ excellence is surprising, because usually a car company’s first crack at a new segment is wanting.

For instance, Toyota’s 1993 T100 pickup, first try at an American-style pickup, was too small and lacked a V-8.

Only now, a decade-and-a-half and two generations of truck later, has Toyota hit the mark with its ultra-beefy Tundra (just when the bad economy dried up pickup sales, alas).

Genesis is Hyundai’s first big sedan and its only U.S. rear-drive model, and it offers the automaker’s first V-8. You can quibble with the timing — small cars and small engines are hot right now — but you can’t argue much against the execution.

Two Genesis test cars, a well-furnished V-8 and a lower-level V-6, were so right that it’s hard to find gripes. Hard, not impossible — though some beefs are pretty minor.

– Front seat didn’t go back far enough for some taller drivers.

– Ride felt bouncy on undulating pavement.

– Console-mounted joy-knob controller on the V-8 tester (like BMW’s iDrive) was simpler to use than most — so only mildly annoying. You still had to go through up to half-a-dozen motions just to assign a preset button to a radio station, for instance.

– The wood section on the steering wheel in the V-8, while handsome, was a reminder that wood is for decks and boats, not cars. Wood steering wheels are cold in winter, sweaty in summer, hard and slippery always. Leather, please.

– The V-8 was jerky on deceleration. To improve mileage, the fuel flow to the engine immediately shuts off when you coast. Nice idea, but a little too abrupt and obvious. Didn’t happen on the V-6, which is tuned differently.

– Mirror-mounted turn signals were annoyingly bright in the driver’s periphery. Move the signals half an inch to solve that. The driver doesn’t need to see them — they’re for the fool in your blind spot who can’t see your rear turn signal.

– Horizontal chrome strips across the dashboard and doors were designed not to mate where those panels adjoin, instead to leave a gap. The strips line up perfectly, but don’t run all the way to the edge of the dash or door. Odd.

To appreciate Genesis, you first have to like rear-wheel drive. Though the BMW and Mercedes-Benz models Hyundai wants to evoke are rear drive, many cars are front drive and have a different driving feel. Rear-drive cars feel more balanced in corners. On the other hand, weight isn’t concentrated over the driving wheels, as with front drive. That suggests worse slick-weather behavior. In the rain during testing, the back wheels spun briefly, but were well-reined-in by the traction-control systems — without abruptly cutting the engine power.

OK, you like rear drive. Now, what’s so special about Genesis? Glad you asked:

– Seats. Leather’s standard; so’s comfort. Back’s angled just so and leg and knee room are plentiful.

– Power. Base V-6 scoots nicely. New V-8 has that kind of always-increasing, never-ending power delivery that Infiniti favors.

– Ambiance. Trim, controls, gauges — elegantly done. Simple lines and curves. Nothing tortured.

– Styling. Smooth, well proportioned, not forced or wannabe. It’ll be as easy on the eye when the loan’s paid off as it is the day you drive it home.

– Safety features. A long list, including standard side-impact bags in the rear seat. Most automakers don’t offer those, and the ones that do charge extra.

– Brakes. Reassuringly firm, but not touchy. Others should copy.

– XM radio. One mode lists all the channels, handy for a satellite system that offers some 200. Makes it easy to find and try something different. No-brainer? Then why’s it rare?

– Persona. Genteel eagerness, backed up by a drivetrain and suspension that deliver.

No, it’s not cheap at $33,000 to $42,000, but neither is it outrageous by today’s standards.

Ignoring price, it’s a credible contender. Considering price, there might not be another car that’s such an all-around satisfier.

What stands out

-Smooth: Everything from the ride to the turn-signal lever.

– Swift: Hyundai’s first V-8 shouldn’t be its last.

-Seductive: Don’t drive unless you intend to buy.

2008 HYUNDAI GENESIS

– What? Full-size, four-door, rear-drive, premium sedan, V-6 or V-8. New to Hyundai lineup.

– When? On sale since late June.

– Where? Made at Ulsan, South Korea.

– Why? Premium car = premium image= premium profits.

– How much? V-6 starts at $33,000, including $750 shipping. V-8, $38,000. Loaded, $42,150.

– How powerful? 3.8-liter V-6 rated 290 horsepower at 6,200 rpm, 264 pounds-feet of torque at 4,500 rpm. 4.6-liter V-8 rated 375 hp at 6,500 rpm, 333 lbs.-ft. at 3,500. V-6 mated to Aisin six-speed automatic transmission; V-8 to ZF six-speed auto. Both have manual mode.

– How lavish? Pretty darned. Standard features include: stability control; anti-lock brakes with brake assist and brake-force distribution; front-impact, head-curtain and side-impact air bags in front and rear; automatic climate control; AM/FM/XM/CD/MP3 audio with input jack; leather upholstery; heated front seats; power steering, brakes, windows, mirrors, seats, locks; rear-window and outside mirror defrosters; cruise control; auto-on headlights; fog lights.

– How big? Small end of the full-size segment. A little shorter, wider than Toyota Avalon. Genesis is 195.9 inches long, 74.4 inches wide, 58.1 inches tall; 109.4 cubic feet passenger space, 15.9 cu. ft. trunk. V-6 weighs 3,748 pounds; V-8, 4,012 pounds. Rated to carry about 1,100 pounds of people, cargo. Turning circle listed as 36 feet.

– How thirsty? V-6 rated 18 mpg gallon city, 27 highway, 21 combined. V-8, 17/25/19. V-6 tester did 16.9 mpg in suburbs. V-8 showed 14.3 in suburb-city mix, 27 in 63 mph cruise-control highway driving, 16.9 in suburban, freeway mix. Tank holds 19.3 (V-6) or 20.3 (V-8) gallons. V-6 takes regular. V-8 needs premium for rated power; regular OK, cuts 7 hp, 9 lbs.-ft.

– Overall: Uncommonly good.

USA Today