yeah, michelin had one too.
Fast Cool Cars - Airless tires - The Tweel - Michelin
I wonder what is keeping these things from coming to market. I'd imagine it's the cost of equipping tire shops with the equipment and knowledge to mount and maintain these tires. and, the fact that the tread is supposed to last 2-3 times as long. If anything, they are even cheaper to manufacture because the tire is just a solid piece of rubber.
But, if I'm not mistaken, the radial tire took about 2 decades to become accepted so maybe the case will be the same for these tires.
Unless their is some hidden negative that we haven't learned of yet, there is no reason that these tires shouldn't be being sold right now.