Here are some terrific Wheelchair costume ideas:
You may have seen this one already - Wheelchair Ice Cream Truck
Cinderella Coach Costume via Family.com
These are great! They are on Specialchildren.com
Those are so awesome!
Aww that is so sweet and really cool.
These could be adapted for strollers and wagons, too. We used to live in a semi-rural area and the walk between houses was quite long so having a ride-on vehicle comes in handy.