I think that this is an excellent test. Accidents almost never happen like the IIHS or Euro NCAP tests the cars. This is actually a somewhat realistic test.
One way to improve crash testing in general would be to show how shifts in weight affect the crash testing.
Another way they could test the cars is test would start them at 60 mph, then at a certain distance hit the brakes as hard as possible (like in a typical accident avoidance scenarios) and not restrict the speed that it hits the barrier. For instance, if my car can slow down from 60 faster and hit the object at 20, it will cause less damage and less injuries than if if another persons car hits the object at 40 because they couldnt slow down fast enough.