I don't know anything about car design, but always assaumed that crumple zones mostly protected passengers rather than pedestrians. Is that not the case?
The front end of your average modern car has a ton of flimsy plastic in the top of the front bodywork that's for pedestrian protection. It's basically a crumple zone but they don't call it that.
Also the hood / bonnet has softening. In a typical collision the pedestrian's head strikes it, so adding some padding under the surface makes it more survivable. I think you get more stars in crash tests.