WASHINGTON -- A federal safety agency is investigating complaints that windshield wipers are failing on some older model Ford Motor Co. cars.

The National Highway Traffic Safety Administration has received 25 such complaints from motorists about Ford Taurus and Mercury Sable cars from model year 1993, according to a monthly agency report released Monday. Some drivers said they were forced to pull over because they could not see.About 555,000 of the popular cars are on the road.

"We're aware of the investigation and cooperating fully," said Ford spokeswoman Karen Shaughnessy.

The agency also is looking into motorist complaints that air bags deployed inadvertently on some Mazda Miata cars from the 1995 model year.

One driver complained the air bags deployed after the car was left parked, and another motorist said the air bags deployed for no apparent reason while he was traveling 25 mph to 30 mph, the report said. Several motorists said their Miatas struck something in the road, in one case an empty cardboard box the size of a briefcase and in another case a curb.

The motorists said the inflating air bags caused one crash and three injuries.

Last year, Mazda recalled the 1995 and 1996 Mazda 626 and MX6 cars after more than 50 motorists complained the air bags opened when the cars hit a pothole or curb, got a flat tire, the driver braked or for no apparent reason.

Also last year, General Motors recalled nearly 1 million autos to repair sensitive air bag systems after more than 300 motorists complained of air bags bursting open without any crash on late-model Chevrolet Cavaliers, Pontiac Sunfires and Cadillacs.