“They had a tire behind the seat just to prop it up, so it really wasn’t very safe,” he said. But it wasn’t much of problem, because Mr. Conaty was attending Fordham in the Bronx and didn’t drive much.

Then he got a ’63 Chevy Corvair convertible, a car that the consumer advocate Ralph Nader called a deathtrap. “I had that for a while after college,” Mr. Conaty said, conceding his affection for the car. “Then I started reading Consumer Reports and getting smart about cars.” The last few years, Mr. Conaty has relied on a series of Mercury Sables for most of his everyday driving.

But he never stopped dreaming about a Nash. So in 2003, Mr. Conaty rejoined the Nash club — he had been a member as a boy — and went to a club meet in Scranton, Pa. He asked around about a car. Sure enough, someone knew of someone who had died, making a red-and-cream Ambassador available.

“I called and made the deal,” Mr. Conaty said, noting his impulsiveness.

“I made the offer without driving it. And when I finally drove it, there were no brakes. I mean to-the-floor no brakes. But I didn’t care.”

Mr. Conaty got the brakes fixed and over the next 13,000 miles — the odometer now reads 66,000 — he hasn’t had much to complain about.

The Ambassador Custom has several distinguishing characteristics. First, there’s the big and bulbous shape. Nash gave a name, Airflyte, to the look. Introduced for the 1949 model year, it was Nash’s first postwar design, and it featured enclosed front wheels for improved aerodynamics.

Nash also increased the turning radius. “When you make a U-turn you kind of have to phone ahead,” Mr. Conaty said as he tried to execute the maneuver on a wide, quiet street. “I’m not going to make it,” he said before resorting to a three-point turn.