Air bags, a matter of contention between the government and automakers for more than two decades, are likely to be as common as rearview mirrors in the 1990s.

General Motors Corp. announced this week that it will put air bags on both the driver and front-seat passenger sides of all of its domestically produced automobiles beginning in 1995.

Chrysler Corp. this year began putting driver's-side air bags in all of its U.S.-made cars. Ford Motor Co. installs driver's-side bags in nearly 40 percent of its cars; Daimler-Benz, Volvo and Porsche include air bags in all of their U.S. automobiles.

That these devices are joining the ranks of such commonplace auto safety items as shatterproof glass and dual hydraulic brakes is a victory for consumer groups and government auto-safety officials who have been pushing for air bags since 1968.

But auto-safety experts and industry officials warn that challenges remain that could serve to impede the swiftness with which these devices are put in place.

There have been numerous problems at plants where air bag components are made, including fires that have restricted the availability of the devices and raised questions about the safety of their manufacturing process.

On the legal front, the auto industry is keeping a careful watch on several lawsuits filed by consumers who charge that the air bags installed in their cars did not function properly.

Chrysler earlier this year was threatened with legal action because air bags in some of its cars inflated too quickly, causing facial abrasions and other minor injuries to drivers. In another suit, Mercedes Benz is facing legal action from the family of an accident victim who charged that the air bag failed to deploy in a rollover accident. The case is still pending.

The devices are inflated within milliseconds by a gas known as sodium azide, creating a balloon barrier between human bodies and hard objects that can cause fatal injuries. Currently, most air bags are installed in the hub of car steering wheels, protecting drivers only.

Chrysler's earlier problems with air bag-equipped cars, in which it drew legal threats from consumers and safety advocates, largely disappeared March 12 when two Chrysler Le Barons crashed in Culpeper County in Virginia.

The accident was the first in which both cars deployed air bags, allowing drivers in each vehicle to walk away from what Virginia state troopers said could have been a fatal event.

Chrysler Chairman Lee A. Iacocca, who once said that safety does not sell cars, used the accident in television ads to boost Chrysler sales.

The lesson was not lost on GM, said Robert Rogers, GM's director of auto safety.

"We think that the market is ready for air bags and that the supplier industry is ready," Rogers said, referring to some early air bag production problems.

The problems involved several fires, which damaged production facilities at air bag plants in Canada and Arizona. According to GM and Chrysler, the problems involved materials used in the production process. While those problems have been identified, auto manufacturers say that their suppliers are still proceeding cautiously in speeding up production.

Still, the outstanding lawsuits and other challenges appear to be giving pause to the Japanese automakers, often regarded as technology leaders in the auto industry, who are still cool to air bags.

"The Japanese car companies are out of touch with the marketplace on this one," said Clarence Ditlow, executive director of the Washington-based Center for Auto Safety.

Some auto-safety experts speculated that the Japanese were holding off on air bags until they could get a better sense of the litigation the devices might generate.

"The Japanese are awfully afraid of lawsuits. If they can avoid litigation by legally substituting technology, they'll do it," said a lawyer for a European car company who asked not to be named.

Spokesmen for Toyota Motor Corp. and Honda Motor Co. disagreed with those accusations but declined to discuss specifics about their plans.

"We originally led the Japanese industry in the usage of air bags, and we intend to continue to excel in that area in the future," said Honda spokesman Kurt Antonius. Seven percent of new Hondas sold in the United States have air bags.

Toyota offers air bags in 15 percent of its U.S. cars. But a spokeswoman for that company declined comment on whether that percentage will be increased in the future.

Although the U.S. automakers in recent years have moved aggressively to make air bags standard features, they have spent decades fighting the idea.

"In 1970, GM promised to have air bags in most of its cars by 1974. But that never happened," said Ditlow. "This time, I believe them. They're going to do it because of federal regulation and the marketplace, which is demanding air bags."

Former secretary of transportation Elizabeth Dole in 1984 set the stage for what would ultimately be a compromise on the issue: She forced automakers by 1989 to choose between state laws mandating seat belt use or a federal regulation requiring air bags or other automatic crash protection devices.

The automakers pushed for the seat belt laws but got statutes that were too weak to meet Dole's demands. American car companies, which at first chose automatic belts over air bags, soon discovered that consumers preferred using a combination of manual belts and air bags instead.