If your DC still uses a carseat, did you use one on the Magical Express? Did you bring your own or does Disney provide them?
My DD, who will be 3.5 for our next potential trip, will still be in a harnessed carseat. She's never been on a bus, and if WDW was a little closer I wouldn't bat an eye to just seat-belting her. I wasn't planning on traveling with a carseat, but maybe I should?