For the 2000 season Irwin was tabbed by Felix Sabates to replace Joe Nemechek in Team SABCO's No. 42 Chevrolet. He had a single Top 10 finish, 4th at Talladega Superspeedway, in his first 17 races with the team. He made nine starts in the Busch Series for SABCO as well, posting a best finish of ninth at Talladega. His final race for the team was at Daytona International Speedway in the Pepsi 400, finishing 22nd; he was seen as having a bright future with the team, which had just had a majority interest purchased by Chip Ganassi.