I've just posted on another puzzle that Moss notably picked the wrong car to drive, or meddled with what he had. The Costin coupe was actually slower than the open cars at Le Mans. I think it was his idea to have the car built. I quote from an excellent work by Mike Lawrence..
"The shell was farmed out to Zagato, which made a complete mess of it.They reversed ducts so that instead of cool air coming into the car, the drivers got hot air from the engine bay; a hole for the radiator cap was cut in the nose, destroying the air flow; the wrong type of windscreen wiper was used, and it blew off; the careful pressure area over the carburettors was altered and starved the engine of air, and, to cap it all, Zagato did not bother to fit the full-length undertray. Aerodynamics were not the Italians' strong suit. Costin took one look at the beast.... and disappeared into the nearest beer tent."
Thankfully, for Moss and Harry Schell, it retired early.
