Business Notes AUTO RENTALS

Most auto-rental customers want brand-new models with few miles on them. But National Car Rental is assembling a fleet for motorists who prefer cars with tail fins, gleaming chrome and wide whitewalls. At several of National's major outlets in Florida and California, the agency has begun offering dozens of carefully restored 1950s and '60s autos. Among them: Thunderbirds, Buick Roadmasters and even Studebakers.

The classic cars cost a relatively reasonable $50 per day and 30 cents per mile, but customers must belong to National's frequent-renter program (fee: $50 per year). The agency finds that drivers treat the vehicles with tender loving care. Says a National spokesman: "The cars often come back waxed and polished -- better than when we rented them."