Leitzinger has driven for the Bentley factory team at Le Mans in 2001 and 2002, for the Cadillac team at Le Mans in 2000 and for Panoz at Le Mans in 1999. Leitzinger has also driven in the GT classification for Risi Competizione at Le Mans in 2003. Leitzinger was also named 2002 Rookie of the Year in the Trans-Am Series. Butch drove the Alex Job Racing (AJR) No. 81 Porsche GT3 car in the first four events in the American Le Mans Series GTC class for the 2010 season, with Juan Gonzales earning victories at the 2010 12 Hours of Sebring as well as at Long Beach and a podium finish at Laguna Seca, resulting in the duo achieving a healthy lead in the points standings before unfortunate circumstances forced Alex Job Racing to downsize to a single-car effort with the No. 23 car for the remainder of the season.