I work for a shipping company, your going to want to pack them seperatly. All 4 wheels in box wont hold up during shipping. I would cut cardboard discs out and attach them to the front and rear of the wheels. Use a box if you can, if you cant, wrap them in skrink wrap very well and place in a some sort of big bag. I assume your going to ship the ground, ground shipments take alot of abuse because of the number of times they are handled, going from truck to truck to truck. Make sure you get insurance.