Complex sentence: She initially hates Jim for apparently his but what was actually Herbie's knee-jerk behavior that ruined her chances of succeeding during the first qualifying rounds due to Herbie sighting and falling in love at first sight with her race car.
Split into simpler sentences: She initially hates Jim for apparently his, but what was actually Herbie's, knee-jerk behavior that ruined her chances of succeeding during the first qualifying rounds. This was because of Herbie sighting and falling in love at first sight with her race car.