Automakers will have to substantially change the way their vehicle interiors' look and function if they plan to do business with an aging and more safety-conscious population, according to design experts.

But carmakers, who possess the technology to accommodate the needs of aging motorists, are lacking a concerted effort to make changes that would be meaningful to buyers whose hearing and sight aren't what they used to be, said several veteran stylists who participated in a symposium recently on interior design, hosted by Monsanto Chemical Co., a supplier of plastics used in vehicle interiors."There is now a level of sameness in exterior car design," said Ron Hill, chairman of industrial design at the Art Center College of Design in Pasadena, Calif., noting carmakers have stepped up efforts to recruit those to the "less glamorous" jobs of interior design.

Hill, who spent 31 years with General Motors, said common design flaws in all vehicles can easily be changed to accommodate the nation's aging population.

"Blue numerals on black (in dashboard instruments) is the worst you can do," Hill said, because as a person grows older, it becomes easier to read larger, yellow or orange numbers instead.

Instrument housings that can be adjusted for distance are also needed. "Many older people cannot focus closer than one meter, or about 40 inches," Hill said.

More upright seating or swivel seats - used by GM in the mid-1970s in some cars - are needed because many older drivers cannot even reach over to change the radio station while driving, or comfortably get in or out of a car.

Participants touched on another pressing issue - vehicle safety, and how some carmakers have done little more than the bear minimum to promote it by only meeting the letter of the law, not its spirit.

Questions were raised about the viability of air bags, to be seen in increasing numbers under a federal law requiring cars made after Sept. 1, 1989, be equipped with passive restraints.

"There is a popular misconception that air bags will replace seat belts, and nothing could be further from the truth," said Homer LaGassey, a retired Ford Motor stylist, now director of design for the Troy Pioneer Group in the Detroit suburb of Madison Heights.

"There will be 3 million air bags on the road by 1990, and people still have no idea what they are all about," said LaGassey, stressing that automakers must educate people about them.

He also asked who might bear the legal responsibilities should an air bag fail to work properly after being stored in a steering wheel or dashboard for years after the car warranty expires.

"Who's responsible? The car manufacturer? The supplier? The dealer?" he said. "The legal profeession will have an absolute ball with this one."

LaGassey, who spent a 47-year career working with all three major U.S. carmakers, said air bags "are worthless" in many accidents that involve a second, third or fourth hit. "They're not much good when they're lying limp in your lap after the first hit."

He said the majority of accidents occur at oblique angles, rather than head on, which raises the question of what can be done to maximize safety in future interior designs.

The greatest factor is the proper use of "body shells" - or seats, in other words.

"The seat is most critical. That's your body shell, or your survival cage," LaGassey said. He stressed that the seat must keep its occupant firmly in place at all times, even during violent crashes.

To do that, he said, the seat should be fixed in place, with the floor pedals and instrumentation adjustable - exactly opposite of what we have now.

Many car interiors still include sharp edges and controls that can cut occupants "like knife blades" during an accident, LaGassey said. An integral structure called a "bird cage" could also be incorporated to make sure the car's "family capsule" remains intact when hit.

"These things can be built today," LaGassey insists. "A NASCAR race car driver will not get in a car without a fireproof suit and four-point safety harness. Aircraft pilots have been wearing those things for 40 years."

Yet every day millions of motorists ignore their three-point seat belts, or shoulder harness - a sad compromise to begin with.

"You can slip out of them on the unlatched side in a strong impact," he said.

Compounding the problem is the development of 140-mph sports sedans that share the same roads as cars driven by older people, who do not have the proper reflexes to safely operate a car at less than half that speed, LaGassey warned .

"We are turning it into the hands of an AARP (American Association of Retired Persons) member - that's the problem," he said.