There is more too it than a "tow eyelet." First off, how many domestic vehicles do you see with this feature, not including pickups. Very few and it is usually a perminantly installed item that is way underneath the bumper or very hidden away. Prior to the Prius, I have never owned a vehicle with this "tow eyelet."

Rather, go to your hatch and take the eyelet out of your jack kit and look at it. It is all scratched up. Why? The eyelet is used during transport on the car ship to keep the car attached to the deck and to prevent it from moving around in heavy seas. The vehicle is attached to the deck at other points, but this is the front mounting and secureing point for the vehicle in transport.

When the vehicles get into port, as part of the the protocols in port, the staff there remove the eyelet, put the plug into the bumper and place the eyelet in the hatch with the rest of the jacking and service items.

It has been said:
Hybrid drivers come in 3 flavors, greenie, techie and cheapie. Pick any 2.
2005 Prius, Melinium Silver over gray, package 5 (AI)