Take the power seat. Leave the sporty coupes to the young folks. Think twice about the navigation system.

That's the advice from experts on cars and aging at the American Automobile Association and University of Florida for older Americans in the market for a new car.

The motorist group and the university's National Older Driver Research and Training Center have issued a guide listing features that older drivers should consider, especially if they face the common symptoms of aging such as stiff and painful joints, diminished visual acuity and increased difficulty in multi-tasking. Both cited government estimates that the number of U.S. licensed drivers age 65 or older will increase from 29 million in 2005 to more than 40 million by 2020.

Recommended items include tilt and telescoping steering wheels, adjustable pedals and power-operated seats, all of which help drivers find a comfortable and safe position behind the wheel.

For those whose hand and finger motions are limited by conditions such as arthritis, the experts suggest looking for thicker steering wheels, keyless entry systems and power mirrors -- the latter two common in new vehicles.

The experts suggest avoiding coupes because their doors tend to be heavier than those of a four-door car or light truck -- and thus more difficult to open and close -- and also tend to be longer, so they allow less room for entry and exit when they're open in tight spaces.

Jerry Poller, 60, a retired bank vice president from Huntington, N.Y., who drives a Volkswagen Passat sedan, said he's sworn off coupes for another reason: cramped back seats -- not for his children but for friends. "If we go out to dinner with another couple or do some local traveling, we want something that will be comfortable enough," Poller said.

The experts suggest shoppers look for vehicles with low thresholds beneath the doors -- something with which driving teacher Mike Melkonian, 83, of Queens agrees. "The footwell, for some people, is pretty deep," said Melkonian, who has been teaching an American Association of Retired Persons defensive driving course for about 20 years. "To lift their legs out is difficult."

The experts recommend gauges that are clearly readable day or night and that controls are large and simple to operate.

John Nielsen, the AAA's Orlando, Fla.-based director of auto repair and buying, said the report's authors disagreed about navigation systems, whose operation can be complex. "I really believe it might help," he said, "but the University of Florida advises that it's really just another noise in the car."

However, Poller said he considers his portable navigation system indispensable when he travels. "If you get a simple unit, a voice unit with some pretty good graphics, they're really not that complicated," he said.

And he said, he'll be seeking in his next new car a couple of relatively new gadgets intended to promote safety: a rear obstacle detection and warning system or a rear-facing video camera for backing. "I would definitely be looking for that in my next car," Poller said.