I have heard, but I absolutely cannot recall where, that while you ARE supposed to leave the wheelchair in the car when you return it (either when handing back, or when getting a new car) that the dealers simply dispose of them and there’s is little to no checking or recording of this so while, technically, legally, no it isn’t yours to keep, it kinda is.
Its almost like the law about all male children having to practice archery once a week – yes, technically it is a requirement, but it’s never enforced.
I have one too, it’s NEVER been used since the day I got it as I was given something absolutely suitable by my local authority – it sits upstairs in the spare room gathering dust. I’m not quite confident enough in my first answer to go out and sell it. but I have no intention of returning it with the car unless specifically requested to do so.
"Man is born in freedom, but he soon becomes a slave, in cages of convention, from the cradle, to the grave."