Looking through some old books I have, and came across "Popular Mechanics D.I.Y. Encyclopedia" and found the plans for the first land yacht I built...... a long time ago 
How did it go? That might be a good school holidays project.
I wish I took a photo of it, but I built a great radio controlled landyacht when I was a kid. The rear axle was a wooden coat hanger and it had model airplane wheels. It used to fly up and down the beach. That was probably when I decided I should go along for the ride. Only took me about 30 years to make it a reality! 
It went very well....faster than a kid can run.
The best set up was adjust the steering to sail a large loop and let it go.
The sail would be better made from a thick plastic shopping bag and sticky tape. But would have to agree a great project for kids....
