Possible Clues:

• Cart came first without a horse
• Vehicles drawn by an animal or a tractor
• Transport vehicle
• Horse-drawn vehicle in the Wild West
• Horse-drawn vehicle
• There's a horse in front of it, and a horse on the end of it
• One, we hear, put a horse, say, inside truck
• Won about a horse for transport
• Won about one horse and something for it to pull
• Four-wheeled drawn vehicle