Maybe I can do something here:function skijumpVehicle::onAdd(%this,%obj)
{
//mount the nothing tire and ski spring
%obj.setWheelTire(0, nothingtire);
%obj.setWheelTire(1, nothingtire);
%obj.setWheelTire(2, nothingtire);
%obj.setWheelTire(3, nothingtire);
%obj.setWheelSpring(0, skiSpring);
%obj.setWheelSpring(1, skiSpring);
%obj.setWheelSpring(2, skiSpring);
%obj.setWheelSpring(3, skiSpring);
%obj.isshiftinggravity=1;
%obj.grav="0 0 -0.5";
skijumpcheck(%obj);
parent::onadd(%this,%obj);
}