THEY WERE Holy Ghost nuns, women from County Cork, Ireland, teaching in New Orleans. Whenever they caught you razzing somebody, they'd grab you by an ear, wag a finger in your face and shout: "Only God is perfect!"

I heard them shouting in my dreams after a week in the 1988 Audi 90 sedan.

What a frustrating machine! The thing is beautiful and tacky, well-crafted and shoddy. Only on the road, 'round the curves and over the hills, does it approach perfection.

Beautiful: The Audi 90's rounded, pearl-white metallic body drew glances from scores of admirers.

Tacky: The seats are covered with sensuous, supple leather. But, yecch! What's this? Junky plastic woodgrain on the dash and center console? Hard plastic covers over the roof pillars? Is this a toy, or a luxury family car?

Well-crafted: The Audi's tightly welded shell is made of high-strength steel, zinc- galvanized on both sides. No dealer rust-proofing or undercoating needed on this one.

The paint job is better than I've seen on any car, foreign or domestic.

Shoddy: The test car's front passenger seat would not move forward or backward because of a faulty adjustment lever. Also, even after releasing all of the power locks, the left-rear passenger door could not be opened from the inside.

The Audi 90, made in West Germany, is one of four cars replacing the Audi 4000 series in the United States in the 1988-model year. The other newcomers include the 90 Quattro, Audi 80 and 80 Quattro.

Audi says that the 80/90 group represents its "efforts to continually push technology forward."

Underline "efforts." The word allows mistakes. The good nuns understand that. But, unfortunately for Audi, they've taken vows of poverty.

General whine: The inconsistency of it all. It's maddening. Living with the Audi 90 is like watching a superior football team throw away a surefire victory with dumb plays. It's like turning in a well-researched, well-written thesis with typographical errors. Makes you wanna screeeammm!

Praise: Despite its flaws, there's lots of excellence in this car. Nifty things, like adjustable door-pillar anchors for the front shoulder harnesses. Short people's necks don't get scratched or cut by belts in the Audi 90, which is no small matter.

Lotsa folks refuse to use shoulder harnesses and seatbelts because the devices can be uncomfortable. Audi has eliminated that excuse here.

Cabin space in this front-wheel-drive car is great for four adults, okay for five of medium build.

Ride, acceleration, handling: When this car is in motion, almost all is forgiven. The Audi 90 follows the road like a bloodhound and moves like a gifted dancer. The choreography is enhanced by a super-smooth, five-speed manual gearbox.

Acceleration gets top marks. The car is equipped with a 2.3-liter, five-cylinder, fuel-injected engine rated 130 hp at 5,700 rpm.

Ah, and braking gets kudos, too. Vented, vacuum power-assisted disc brakes up front, solid discs in rear. Anti-lock system. This car stops.

Sound system: Audi-badged AM/FM stereo radio and cassette, anti-theft model, six speakers. Terrific.

Mileage: A respectable 24.5 miles to the gallon (18-gallon tank, estimated 430-mile range on usable volume), heater on, driving in the District of Columbia and through Virginia's stunning Shenandoah Valley.

Price: $24,665, including $335 in destination charges. Base price is $24,330. Dealers'invoice price is $20,193.90.

Warren Brown covers the auto industry for The Washington Post.