I don't know of one, but a friends Uncle made an adapter for his years ago so he could pull it behind his golf cart. He had a fairly level yard but wanted the comfort of the golf cart.

He took the bag off of a pull behind lawn sweeper and bolted on a 10" pvc pipe that he cut in half. Then made an adapter so that he could hook the hose from the vac on one end. He mounted it under the front of the vac with pivoting arms so that it could move up and down with the terrain.

It worked pretty good as long as the leaves were bone dry.

I wish I had a picture of it to show you since my explanation is probably hard to figure out!

Check the big box stores, i think i saw one being assembled today.