Contreras made his first Busch Series attempt in 2002 with the Hispanic Racing Team. Driving the #09 CICLON Energy Drink Chevrolet at Homestead-Miami he was unable to break into the field. He would his debut in 2003 with Jay Robinson Racing. At California Speedway, Contreras put the #49 Fox Sports Espanol/Citizen Watches Ford in the field and finished in the 26th position. He also made one start for Innovative Motorsports at Homestead-Miami. He drove the #48 Scunci U Style/Goulds Pumps Chevrolet to a 17th place finish. In 2005 he would return to the Busch Series with Fitz Motorsports. He drove the #40 Dodge in five races and the #12 Dodge in one race. His best finish would come at Homestead-Miami, where he would finish 25th. For the 2006 season, Contreras has again returned to Fitz Motorsp