The C5-R was fitted with a 5.5-litre Chrysler V8 engine capable of generating 310 bhp at 5200 rpm, and could reach speeds up to 249 km/h despite weighing a bulky 2590 lb. It featured a front beam axle suggested by racecar engineer Kurtis Kraft, who used such a feature on cars he designed for the Indianapolis 500. For front and rear suspension, a torsion bar system was used. The C5-R was built using an aluminum tubular frame.
The vehicle was entered in the 1953 24 Hours of Le Mans race, where it was driven by Phil Walters and John Finch and ultimately finished in third place, only being bested by two Jaguar C-Types. After the race, Cunningham criticised the C5-R for its lack of disc brakes. In his view, this was the reason for his defeat, because the Jaguar C-Type already used this new braking system.
The vehicle was subsequently rolled by John Fitch at the 1953 12 Hours of Rheims race, and underwent reconstruction in the United States, where it was rebuilt around a spare chassis. Cunningham attempted to acquire disc brakes for the vehicle during the construction process, but was incapable of receiving such brakes, and thenceforth began focusing on a newer model, the C6-R. The C5-R competed in a handful of races after being repaired, and was later sold to racecar driver Charles Moran at the end of 1953.