theres nothing to stop individuals funding their own car or taking out a private lease or hp agreement.
occasionally there are deals to be had, there was one for jeep compass that was as good if not cheaper than motability.
but i suspect like others what he wants are vehicles that are currently outside the cap.there has to be a limit in part due to the weekly amount to fund the lease and partly to keep the ap reasonable. if someone can afford a huge ap larger than is currently allowed then they can afford to go private. but of course they want motabilities buying power to reduce the cost for them so they dont have to pay list price.