By about 1991, the average automobile will have more on-board computer power than the Apollo moon landing ship did in 1969, says Tom Peters, best-selling author and management consultant.

Approaching your car, you push a button on your personalized key ring to unlock the door. That triggers the driver's seat into its preset position, one that includes distance from the wheel, elevation, lumbar fit, side-bolster angle, thigh cushioning, steering-wheel attitude and rear-view placement.Your special key also whizzes the radio to your favorite station at your favorite volume and sets the climate controls for your comfort.

"Windshield wipers," you say. And on they come, activated by the voice recognition system (we'll learn to call it VRS).

A glance at the small TV monitor on the dashboard gives you a live view from the back of the car. Instead of a rear-view mirror, this car has a CRT (cathode-ray tube) video monitoring system.

The engine winds up and hums. You are leaving the 20th century behind.

Pulling up to a curb in your 2002 model, the four-wheel steering makes parking as easy as one-two.

After you turn off the engine and walk away, you can't resist looking back at this streamlined machine. It's low-slung in front and sweeps back toward the haunches from its chisellike nose that promises to slice through the wind.

Its shimmering windshield wraps deeply around to the rear posts. The curved glass also is the roof, darkened by an opaque switch, and it blends into the steel skin of the rear deck in a seamless swoop.

Some of the improvements will appear as soon as five years from now, and by the year 2000 personal vehicles are going to be tremendously improved, industry spokesmen agree.

They will be dramatically different from what they are now, says James C. Leslie, a top Detroit automotive engineer since 1971. Vice president for engineering with TRW Transportation Electronics Division at Farmington Hills, Mich., Leslie spent 16 years with Chrysler Corp. and Ford Motor Co.

Jerry Rivard, an industry consultant in automotive electronics and former chief engineer at Ford, says the industry's major advances are being made possible by more sophisticated electronics that are changing the way cars will be designed, built and driven in the decade ahead.

About 15 years ago, electronics was introduced in cars. Now, Rivard said, "electronics systems are becoming a primary tool in the total integrated design of the car."

Automotive electronics would have developed more slowly had it not been for concerns about fuel consumption and emission controls in the 1970s, he says. "The big drivers in pushing electronics along were emission laws and fuel constraints."

In the near future, Rivard says, cars will incorporate designs for power train, braking, steering, suspension and other systems that will interact and produce "a very good ride, very good handling, a more consistent vehicle."

Advanced electronics is dominating components being developed now for the 1990s:

-Electronics-assisted steering, for example, will alter the angle of the wheel and column so that seat backs can be raked further back and permit a lower roof-and-windshield slant for better aerodynamic lines.

-Your speedometer reading will be projected on the windshield at a convenient vision level. The function, called "heads-up display," is borrowed from aircraft. Other readings that might be shown this way are turn-signal blinkers, warning lights or other emergency information. You will be able to adjust the display to make it higher, lower or brighter, and because it has the car's hood as background it will not disrupt your view of the road.

All such new options are very expensive, Leslie says. "They are high-priced at first to pay off costs of engineering, design and tooling." If they become popular, increased production will bring costs down.

-Other features already in prototypes or in limited production that make driving easier are heated windshields, mechanized seat belts, air bags and sensor-activated day-night mirrors.

-An adaptive suspension system will enable a car to bank into a turn instead of rolling the opposite way.

-A switch will alter the suspension from the sporty, stiff-riding vehicle you like to the smooth, touring comfort preferred by your spouse.

-Major changes in the engine will be spearheaded by greater use of aluminum and composite materials. Such weight reduction will lead to fuel economy, engine efficiency and fewer vibration problems.

-A spare tire that never needs air already has been perfected by the Uniroyal Goodrich Tire Co. Made of elastic polymer, the non-pneumatic spare is puncture-proof and requires 40 percent less space than today's mini-spares. Because federal standards have not been developed for testing this type of tire, the soonest it could be on the market is the 1990s.

-The car with a brain of its own is expected within five years.

Future electronics developments include sensors, computerized logic and memory functions that will enable a car to diagnose its own problems.