My idea is adding vehicles because some people might be building something like a empire which would have cities spread out so they would want a fast way to get their... or they would want a vehicle just so you could drive around or say have an AI be driving (Hint Hint) and then you be in shotgun firing at pigs with a bow and arrow. it would also not limit you to having just a mine cart on wheels, it could be a full fledged car, jeep, semi. And for those people that have online Army PVP servers... you could get a whole group of people in a car and head to enemy base or simply anything from firing a explosive bullet from a tank into a window or flying over with helicopters or planes and it would also just look pretty cool