How to Make Your Car a Concours Winner: The Dos and Dont's of Car Care

For decades, the high-stakes world of concours judging has had a reputation for rigid perfectionism. Stories abound of judges donning white gloves to check for soot inside exhaust tips or deducting crucial points for a single stray pebble wedged into a tire tread. But as collector demographics shift and a new generation of enthusiasts enters the hobby, the philosophy behind car judging is undergoing a massive transformation.

In a candid interview, Nigel Matthews—Global Brand Ambassador for Hagerty, licensed automotive technician, and Chief Judge at prestigious events like the Amelia Island, Greenwich, and Las Vegas Concours—brakes down the ins and outs of vehicle evaluation, detailing mistakes to avoid, and why over-restoration might actually lose you top honors.

The Birth of the M100 System: Rewarding Patina and Usage

Traditional 100-point judging systems leave virtually zero wiggle room for real-world usage. Under strict point-deduction formats, an untouched "garage queen" that has never seen daylight will routinely beat an iconic, historically significant car simply because the latter has stone chips from actual driving.

To fix this flaw, Matthews co-created the Modernized 100 (M100) judging format—a system that took three years to develop.

Instead of scoring out of a strict 100 technical points, M100 caps technical scoring at 95 points. If a car earns 95 technical points, it is considered a functionally perfect 100-point car. The remaining 5 points are granted at the judges' joint discretion.

This allows judging teams to elevate a driven car with incredible provenance—such as a 1959 Ferrari 250 Testa Rossa raced at Le Mans—over a pristine modern supercar that has never left a climate-controlled trailer.

The Top Mistakes Owners Make at Judged Events

Whether you are competing at Amelia Island or entering a local weekend cruise-in, small technical errors can derail an otherwise flawless restoration. According to Matthews, these are the most common pitfalls:

1. Generic Hardware and Modern Batteries

When restoring a vehicle to concours standards, factory OEM accuracy is key. Two of the most frequent deduction causes are:

• Generic Hose Clamps: Replacing original factory-style clamps with modern, worm-gear hose clamps bought at a local hardware store.
• Modern Batteries: Installing sealed, dry-state batteries instead of period-correct lead-top batteries.

2. Over-Restoration

Believe it or not, a car can be too perfect. Concours events are designed to preserve vehicles as they originally rolled off the showroom floor. Over-chroming, applying modern high-gloss finishes where factory lacquer belonged, or spending six figures to turn a mass-produced 1930s Ford into a flawless piece of jewelry will result in deductions for over-restoration.

3. Cleaning Disasters

• Dish Soap Danger: Avoid using dish soaps like Dawn to wash your vehicle. While effective at breaking down grease, dish soap strips away carefully applied wax and protective coatings instantly.
• Toxic Wheel Cleaners: Aggressive mag-wheel cleaners can strip protective plating off chrome or zinc-coated lug nuts, leading to rapid rusting down the line.
• Ammonia Glass Cleaners: Ammonia-based cleaners used on interior glass can damage adjacent plastic trim and accelerate material breakdown.

Common Myths vs. Concours Reality

Preserving History: From Buried Treasure to Best-in-Class

Ultimately, car judging isn't just about handing out plaques—it's about historical preservation and storytelling. During the interview, Matthews shared the extraordinary story of a Bristol 400 in India—the only one ever exported to the country.

The vehicle was discovered literally buried underground in dirt. After a painstaking 11-month "resurrection" rather than a mere restoration, the car was dug up, fully rebuilt, and went on to win its class at the prestigious Cartier Concours.

Nigel’s Top Advice for Car Show Entrants

1. Know the Judging Style: Research whether the show judges on factory authenticity, detailing/cleanliness, or a popular vote so you can prepare accordingly.
2. Respect the 15-Minute Window: Judges typically have about 15 minutes per car. State the facts clearly, answer questions directly, and don't waste precious minutes flipping through a 3-inch photo album.
3. Tell Your Story: If your vehicle has been in your family for generations or was built with sweat equity in a single-car garage, let the judges know. History and passion matter.

Watch the Full Video Interview

Want to hear the full discussion—including wild stories about clock-rigging at Pebble Beach, rampant bribery at the Concours d'Lemons, and Nigel's driving adventures in India? Watch the video above.