struct SVehicleMovementEventParams {
  Vec3 vParam;
  float fValue;
  int iValue;
  bool bValue;
  const char* sParam;
  IVehicleComponent* pComponent;
};

IVehicleSystem.h

bool bValue;

float fValue;

param for e.g. damage value

int iValue;

IVehicleComponent* pComponent;

optionally, vehicle component involved

const char* sParam;

Vec3 vParam;

param for hit pos or others

SVehicleMovementEventParams();