DETROIT – Everyone has his own ideas as to what makes for a luxurious car interior, but automotive consultant Robert Eller has a list.

He also has a list of what premium auto makers shouldn’t put inside their occupant compartments.

If you charge $40,000 or more for a vehicle, avoid interiors with glossy plastics “that look like plastics,” visible airbag seams and 2-tone colors, Eller, president of Robert Eller Associates Inc., says at the 2007 Ward’s Auto Interiors Show here.

Although he advises against bi-color schemes that look good on golf shoes but not in luxury cars, he’s against the all-gray interior look, as well.

“All-gray is boring and cheap looking, and people are tired of it,” Eller says during a panel discussion on creating a premium interior environment.

He says the latest up-and-coming premium interior color is piano black, a jet-black hue that’s gaining popularity in Europe

Eller’s idea of a perfect premium interior includes leather seats with a soft, glove-like feel (”not pleather”); heated steering wheel covered in double-buffed leather; real woods; matching grains (”people do notice”); low glosses; soft touch points; diffused lighting (”not directed and harsh”); and attention to stitching.

Materials in luxury car interiors need not cost a fortune, says Robert Brooks, executive director of Draexlmaier System Technology North America, an upscale automotive supplier.

What’s more important is that the materials exude craftsmanship, “like fine furniture in a home,” Brooks says. “The process of installing the material can be more important than the material.”

For example, a bad-stitch job with premium leather is inferior to French stitching on regular leather, he says. “Craftsmanship is an interior value that influences purchase decisions.”

Trims are an important element of how interiors are perceived as premium, Brooks says.

His firm offers a variety of wood trims, including ash, chestnut, walnut, oak, birch and bamboo. Grain matches are important, but the darker the color, the harder the match, he says.

He points to the ’07 Cadillac SRX as an example of “an elite level of craftsmanship” using Pommele Sapele African wood to achieve “quite a premium look.”

Consumers are conditioned to expect premium offerings in virtually every automotive segment, says Nik Endrud, director-marketing and benchmarking for Faurecia North America Inc.

The new Saturn Aura features an interior with a premium look, yet “proves a premium interior need not be expensive,” he says. “Saturn as a brand is moving in that direction.”

“In today’s market, every consumer is a potential premium buyer,” Endrud says. “Some consumers splurge on a few things and buy discount for everything else.”

He tells of a man who owns an Infiniti M35 but lives modestly in all other ways.

sfinlay@wardsauto.com