Just to add to what @kezo said, the car must be unregistered so that Motability is the first owner. I do believe there is a process where a dealer can de-register a car under certain circumstances but it does rule out ‘demonstrators’.
There is a pinned thread at the top of the forum homepage which lists dealer ‘special offers’ and sometimes contains cars that are ready-to-go from dealer stock (although you may have to be prepared to travel to a dealer some distance away to order the car, and then again to collect it -servicing etc. can be carried out at your local dealership though)
Sean
Current car Hyundai Kona Ultimate EV