IMO, the most important update damage wise is the suspension and wheel(rim) damage. The reason for this is to force people to be more concerned about running over curbs at 90mph (namely FB Green) and worry if their suspension will collapse the first time rather than 50 laps of hitting the same curbs.
Not only would hitting high curbs at high speed damage the suspension, but would also damage the steering column, the toe and camber, the dampers, the rims, etc.
At the moment(from now and the next patch) IMO, parts falling off is not that necessary compared to these things.