Complex sentence: He was the Grand-Am GT Series champion in 2002 and 2004, and scored back-to-back Driver's Championships in 2003 and 2004 in the SPEED World Challenge Touring Car series, driving with Turner Motorsport.
Split into simpler sentences: He was the Grand-Am GT Series champion in 2002 and 2004. And he scored back-to-back Driver's Championships in 2003 and 2004 in the SPEED World Challenge Touring Car series, driving with Turner Motorsport.