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.

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 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 Vaughan, design leader for 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, Vaughan 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,” Vaughan 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 the instrument panel, center stack and door trim.

“The color of lighting influences the well-being of people in the car,” says Herbert Wambsganss, director-engineering for Hella's interior lighting division.

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.”

For complete conference coverage, go to AutoInteriors.com