The only C-5R ever built featured a narrow tube frame with outriggers to mount the aluminum body, whose design was supposedly approved by Bonneville craftsman Reid Railton.

While appearing to be a step back in terms of sophistication, the straight-axle, torsion-bar front suspension saved 30 pounds of unsprung weight and eliminated the tire scrub caused by camber changes inherent in the previous independant layout. The live rear axle also employed torsion bar suspension in place of coil springs.

The C-5R's higher speed capability presented the need for better braking, resulting in the largest brakes (seventeen inch diameter) ever fitted to a modern-era racer. They proved inadequate however against the lighter, slower but disc-equipped Jaguars. The C-5R was faster on the Mulsanne Straight by five mph, but it could not outbrake the Jags. Even so, John Fitch and Phil Walters eventually brought the car home in third place.

Shortly after the 1953 Le Mans, the team travelled to the champagne district of Reims for a new twelve-hour sports endurance race in support of the French GP. The event was a memorable one: Alfred Momo introduced Briggs to Juan Manuel Fangio, whose invitation to a friendly toast introduced Briggs to the joys of champagne, and John Fitch survived a gigantic, end-over-end wreck in the C-5R. The car was returned to the U.S. and rebuilt. The team finished the '53 season with still more wins in the U.S. and fresh ambitions for yet another run at Le Mans.