DEARBORN, MI – With car interiors, if it looks good, it also must feel, sound and even smell good, says John Puskar, director-cross brand strategic design for General Motors.

“When you have all the senses right, you get harmony,” he says at the Ward’s Auto Interiors Conference here.

Puskar describes a routine of sitting in a car with his eyes closed, running his hands over surfaces and listening to the sounds door locks and other devices make when activated.

“Is it a pleasing sound or does it sound like a chicken bone snapping? If a rotary knob looks nice but doesn’t feel that way, we’ve lost them,” he says of today’s discriminating car consumers.

He speaks at a session, “Designing Interiors for All Five Senses.” Despite the title, panelists note the sense of taste is not truly part of auto-interior design.

“I won’t ask you to taste interiors,” says Richard Vaughn, design leader for auto supplier Visteon. But “taste” in the form of perceived and preferred quality is real, says moderator Rose Ryntz, director-material engineering for IAC. “Design appeals to taste.”

Puskar speaks of yet another sense. “The emotional experience – what I call the ‘sixth sense’ – comes from a correct combining of all the other senses.”

Taste varies from country to country, which designers must keep in mind, Vaughn says. “It is critical to understand the environment for which we are designing.”

Even regions of the same country can reflect widely different preferences, he says, citing India, a vast country in which religions can influence color preferences.

“Orange, or saffron, often is associated with the Hindu religion and green with Islam,” Vaughn says. “As designers, we have to know what we are doing.” That includes regionally offering interior lighting colors “that avoid problems.”

Just as the original Model Ts came in one color, black, interior lighting of yesteryear came in one, white. But today’s ambient interior lighting crosses the spectrum with an array of colors to accentuate various sections of a car, including the instrument panel, center stack, door trim and headliner.

“You can do a lot with lighting,” says Herbert Wambsganss, director-engineering for auto supplier Hella’s interior lighting division. “The color of lighting influences the well-being of people in the car.”

Ambient lighting’s full effect is experienced during night driving. That can make it hard to sell lighting options to customers in a brightly lit dealership showroom, he notes.

Mercedes-Benz addressed that problem by creating brochures with photos illustrating ambient lighting “so people can see what they are paying for,” Wambsganss says. “The take-rate soared.”

Asked if the future might hold better ways, such as in-dealership simulators, to get the lighting point across, he says, “That would be nice.” He then refers the question to the auto maker representative on the panel.

“Lighting is so important; we’ve done (showroom simulator) mockups,” says GM’s Puskar. “It will be a trend going forward.”

Also in the future are advancements in allowing buyers to personalize interior lighting, including the colors and areas of the car they may wish to illuminate. “Maybe you will be able to download preferences, so you can really have a personalized car,” Puskar says.

Customer preferences vary greatly, particularly by vehicle segment, says Vaughn.

The Kia Soul, aimed at young buyers, offers ambient lighting that beats to music from the sound system, he notes. “That would not be appropriate for a Mercedes buyer, but it is to a Soul buyer.”

The way things are going in the industry, an interiors panel discussion on appealing to the five senses, even six, might fall short, quips a conference attendee. “Maybe we’ll have seven.”

sfinlay@wardsauto.com