If you will usually be taking two scooters along, I would favor a small trailer to carry them and other stuff. A cover of some sort would keep road grime and rain off the scooters, etc. I have carried my old Honda Trail 90 on a rear carrier but bike obstructs access to the rear cargo bay door while underway and any extra weight on the rear makes the rig lighter on the front wheels affecting handling somewhat. A bike on the front restricts access to engine. It also takes some effort to dismount and mount scooters etc. on a hitch rack