The Art of Making a Classic Car Ready for Its Close-up

Shining his work light into the deepest recesses of a Ferrari F512 M’s engine bay, Tim McNair takes note of minor flaws that will warrant closer attention. There’s an oily smudge on the intake plumbing, chipped paint where red shows through on the black chassis tubing, a damaged sticker on an ignition coil — typical signs of use in a 30-year-old car — and all readily dealt with.

Making them right won’t be a problem for Mr. McNair, whose credits include preparing a Ferrari Enzo that was awarded a perfect 100-point score at the Cavallino Classic, where the brand’s cars are evaluated by judges.

But the wrinkle-finish paint on the engine is another matter. That color, silver, and in that finish with an attractive crinkled texture found on many Ferrari engine castings, simply isn’t available in a quality that satisfies him.

For Mr. McNair, owner of Grand Prix Concours near Philadelphia, it’s all in a day’s work. His livelihood is making sure that collector cars arrive at premier competitions as perfect as possible. Far removed from the casual bucket-and-sponge routine of an owner preparing for the local cars and coffee, the stakes of Mr. McNair’s work run much higher. His subjects will be scrutinized at formal events like a concours d’elegance, a beauty showcase typically featuring classics revived by seven-figure restorations.

So when a client gives him a car to prepare, he cleans, polishes and corrects flaws. With judges — likely including experts steeped in the minutiae of just what type of hose clamp or headlight bulb is correct for that year and model of vehicle — working to exacting guidelines, a concours demands precise preparation. To be a best-in-show contender, a car must be more than spotless; it needs to be factory-accurate in myriad details.