My main complaint with the Sun Mountain Speed Cart (push cart) was that the tires would constantly go flat because of stickers. I like that kind of tire on push carts, but it would need to be a no-flat design...solid rubber maybe. I gave my Speed Cart away because of this problem.

For something that probably hasn't been done before, why not have a portable cart that can not only move itself (already available) but give the player a ride, too.