If I understood that correctly; when the front gets light having unlimited rebound allows the suspension springs to help push the body of the car away from the ground. An effect partially limited by the dampers. In that case the body of the car would jump up in a sort of pogo stick effect and the higher it goes the more heavily it is going to crash down. If the car is going over a crest at speed it could travel quite some distance before it drops down again and all the while the ground is getting further away.

Peter

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