That "Bumper Thing" is not on the white car because the white car is one of the "concept" show cars, not one of the "mules". There will be some sort of rear bumper to meet fed standards. Not as ugly as the mule shows, but not as slick as the concept car.
Understand that Ford because of corporate policy will meet the standards to the letter of the law. Some "exotic" manufacturers may stretch the letter of the law and operate under the the "best intentions" concept. They may be able to make a slicker looking vehicle becuase of this.
Rick
