Maybe I’m missing something, but what money has been wasted?
Almost all applications on Motabilty are now automated online, including the DLM / DVLA / DWP checks needed and the car is owned by the manufacturer / dealership and will still be sold from stock to someone else for almost certainly more money than Motability would have paid for it.
About the only person that may have had some time wasted is the salesperson at the dealership …. and they were getting paid anyway?
Dealers know that the car is only sold/leased at the time of handover, and they still partner with the scheme.
The point for any reason is that the final suitability checks (wheelchairs fit, the actual car has seats that work for the disabled person* etc) can only be done on the actual car that’s being leased.
If the disabled person isn’t happy then they must have the right to cancel the application; it is an exchange for a disability benefit at the end of the day and that benefit is paid out to assist it’s beneficiary
*Most test drive cars are not the same spec as the leased car