Pamster...

I'll be keeping you both in prayer as well.

I don't know a lot about the different kinds/levels of autism and which is the best way to guide them in these instances....so I admittedly may be way off here....but I'm guessing that there must be some reward your son perceives in making a game out of taking away your w/c. He's getting something out of it, or else he wouldn't be doing it. It's possible that the 'reward' is your reaction and/or the action of you hopping/scooting. Each time this happens, it reinforces his behavior.

I wonder what would happen, over time, if you simply didn't react? And that would include not responding to him in any way, shape or form as long as your w/c is not accessible to you. Again, I don't know how your son learns best, (or how long you'd be left stranded without your w/c! ) but it may become more desirable for him to have your interaction again, rather than trying to elicit another hopping exercise from you. (?)

I'm sure you've tried everything imaginable, so I hope I haven't insulted you with my simplistic advice. I only want for you to have your w/c!! That must be wearisome for you to go through each time. Please let us know how it's going.