I thought it'd be cool if it was possible to attach carts to horses. I know right now you can right click on a cart while being on a horseback, and that's really cool, but wouldn't it be cooler if you could say right click on a cart, then right click on a horse and select "attach cart" or something, and have this horse with a cart until you right click the horse and select "detach cart", otherwise every time you hop on that horse it will always have that cart follow it, and always stand still when u aren't on that horse or don't have a rope on it to follow you.
I'm also pretty sure a lot of people thought if it before, but wouldn't it also be great to be able to "Avast" the cart and be a passenger? One problem I see though is, horse shouldn't be able to run away while in a fight, or detach the cart when it enters combat, otherwise you'll be able to travel at a speed of light in a random direction sitting inside the cart after you or someone else deal enough damage to the horse to start running away. Of course 6 people would be too many inside a cart, so maybe 1 or max of 2 sounds more reasonable.