Complex sentence: He ultimately took 4th in the championship, ahead of the factory Honda of Karl Harris, whose ride he took for 2007, alongside reigning champion Ryuichi Kiyonari of Japan.
Split into simpler sentences: He ultimately took 4th in the championship, ahead of the factory Honda of Karl Harris. He took Harris' factory ride for 2007, alongside reigning champion Ryuichi Kiyonari of Japan.