THE 1990 Infiniti M30 coupe is one of those parties where everyone is trying hard to be someone else. The car is painfully self-conscious, awfully insecure. It creates more stress than joy. It makes you want to leave early.

Unfortunately, though, Infiniti M30 buyers don't have that choice. Most of them will have to live with this car three years or more knowing that they could have done better buying a Nissan Maxima SE sedan, or a top-notch Honda Accord, or, for that matter, a Toyota Celica or Pontiac Grand Prix.

Nissan's Infiniti group is another one of those luxury-ueber-alles divisions meant to lure buyers away from Mercedes-Benz, BMW, Porsche, Audi, Cadillac, Lincoln and Jaguar. And like Toyota's Lexus and Honda's Acura, Nissan's Infiniti has gotten it only half-right. The Infiniti Q45 -- the real Infiniti -- is a truly excellent luxury car. But the lower-priced M30 proves that in their haste to pull buyers into their new luxury divisions, the Japanese car companies have resorted to the same product-proliferation schemes that hurt U.S. auto makers.

Background: Nissan launched its Infiniti group this year to compete with Honda's Acura and Toyota's Lexus cars. The Infiniti Q45 is gaining in public esteem, but the M30 -- the division's "price leader" -- has not ignited buyer passion.

Complaints: Boredom is anathema in the luxury class. The M30 is dismally boring. It has no soul, no passion, no sass. It's a sports coupe without sportiness. It is a linear bit of reality that inspires nothing.

Praise: The Infiniti M30 proves that the 1990 Nissan Maxima SE is a terrific buy. Yeah, I know: The Maxima is a four-door sedan and the M30 is a two-door coupe. Big deal. Which would you prefer? A hot-to-trot four-door sedan that knows what it's about, or a neurotic "sports" coupe that's still trying to find itself?

Head-turning quotient: A complete zip.

Ride, acceleration and handling: Excellent in all three categories. But, again, so what? The Maxima, Celica, Grand Prix, Accord and legions of other cars all do just as well. In a number of cases, the rivals do better.

The rear-drive, four-seat M30 is powered by a three-liter, fuel-injected V-6 engine rated 162 horsepower at 5,200 rpm. Of course, it moves. Disc brakes are at all four wheels, and they're backed up by an anti-lock system. The M30 stops well, too.

Sound system: AM/FM stereo radio and cassette. Nissan installed. Excellent, especially with Bose speakers. But takes third place to General Motors Corp.'s Delco/Bose sytems and Ford's JBL boogie boxes.

Mileage: About 23 to the gallon (17.2-gallon tank, estimated 385-mile range on usable volume), running mostly highway with two occupants and full-time air conditioner use.

Price: Base price is $23,500. Dealer's invoice price is $18,800. Price as tested is $23,850, including a $350 destination charge. The price includes a four-speed automatic transmission, driver's-side air bag and power sunroof.

Purse-strings note: Even with the M30's impressive list of standard equipment, I think the Nissan Maxima is a better buy -- because it's a more enjoyable car. But, hey, if all you really want is an Infiniti label, go for the M30. It's your money.

Warren Brown covers the automotive industry for The Washington Post.