The Mac3, in conjunction with the older M1 model, helped Centenari to take joint-second in the 1998 International Sports Racing Series CN Team's Championship.
For 1998, Centenari developed a new car for the International Sports Racing Series (ISRS) – the Mac3 – and the team expanded to a two-car effort, with the older M1 being retained.
The team started their season at the 1000 km Monza, which was part of the GT Italian Challenge and the Challenge Endurance Italia, with Loic Depailler, Xavier Pompidou, Giovanna Amati and Marco Lucchinelli driving the new Mac3, and Merzario, Giovanni Li Calzi, Robin Donovan and Fulvio Ballabio driving the older M1.
[12] Centenari were classified joint-second in the CN Team's Championship, and eleventh overall, at the end of the ISRS season.
[21] Centenari entered João Barbosa, Georg Paulin and Andrea Piccini in the Mac3 at the 6 Hours of Vallelunga, but retired after 53 laps.
[22] In 2001, "Gianfranco", Pfyl and Walter Margelli were the car's most regular drivers; "Gianfranco"'s best finish was a fourth at Misano on 8 July,[23] Pfyl's was a second at Dijon on 15 April,[24] whilst Margelli's best finish was fourth at a race held on the Autodromo del Levante on 23 September.