Jean Rondeau commissioned a team of engineers to create a genuine clean-sheet Group C car after the M382 had demonstrated that the previous generation's architecture — rooted in the M379 — had reached its limits. Don Foster designed a new chassis, while aerodynamicist Max Sardou created a rounded, voluminous body shape. The most distinctive feature was the rear section, which used a Venturi channel intended to generate downforce on the rear axle through the Venturi effect.
The execution of the Venturi tunnel introduced a fundamental problem. To accommodate the large tunnel geometry, the exhaust pipes had to be routed alongside the radiators on each flank of the car. This arrangement severely restricted the radiators' cooling capacity and led to persistent engine overheating. A heat shield was added between the exhaust pipes and radiators to mitigate the problem, but it never resolved it fully. During test driving, engine wear was already notably high, and the issue did not diminish in race conditions.
Power came from the Cosworth DFL V8 in its 3.9-litre form, the same unit used in the upgraded works M382.
The M482 made its competition debut at the 1982 6 Hours of Silverstone. Jean Rondeau and François Migault drove chassis 001, but the car's deficiencies were immediately apparent. In qualifying, the M482 was sixteen seconds per lap slower than the pole-sitting Porsche 956 of Jacky Ickx. Even the works M382 and a private M382 were faster. The car retired after sixty laps with suspension damage, its only competitive outing of 1982.
Shortly after the 1982 season, Jean Rondeau withdrew the factory from sports car racing. Financial difficulties combined with disputes with the FIA made continuing unviable in the existing form.
Ford France acquired the three existing M482 chassis in early 1983 with the aim of entering them at the 24 Hours of Le Mans. The venture became a disaster from the outset. In practice, the cars' high rear downforce left them critically slow on the long straight sections. All three retired early in the race. Jean-Pierre Jaussaud and Philippe Streiff's car developed an irreparable oil leak after just twelve laps. Jean Rondeau driving alongside Alain and Michel Ferté retired after ninety laps with engine failure, and Henri Pescarolo and Thierry Boutsen ended their race after 174 laps, also with engine failure.
Ford sold the three chassis to private teams at the end of 1983. At least one M482 continued to appear at Le Mans each year through 1987. The type's best overall result came in that final season. Chassis 001, entered by Graff Racing for Jean-Philippe Grand, Gaston Rahier, and Jacques Terrien, finished twelfth overall, though the car finished 95 laps behind the winning Porsche 962C of Hans-Joachim Stuck, Derek Bell, and Al Holbert.
The M482 stands as a cautionary example of how a technically innovative concept can be undermined by a fundamental packaging conflict. The Venturi tunnel that defined the car's aerodynamic ambition made proper cooling impossible to achieve within the available space. Although the car reflected Rondeau's aspiration to build a genuinely modern Group C prototype rather than evolve an older design, the inherent fault was never corrected during its racing life. Its extended presence at Le Mans in privateer hands after the factory's departure was a consequence of the low cost of the available chassis rather than any competitive relevance. The M482 is principally remembered as the point at which the Rondeau factory's direct involvement in Group C effectively ended.