If it were a scheme to have 50% UK built cars then yes - but it may well exclude cars that we all think are British ie Minis.
I can understand this.
But it's also quite hard to define a British built car. Is it value of content? Final assembly? Is it British ownership of the company?
If the move is fuelled by optics - not a good look to have the disabled 'owning' premium makes of car. (shades of wanting to get them back into the old pale blue Invacars)
Then it's less good.
Some premium brand cars are a good buy overall. Depends on how you look at the finances.
This is demonstrated by the rates - often cheaper to get a BMW 1 series on PCP than a Ford Focus etc. A 3 series cheaper than a Skoda Superb.
Similar, behind the scenes, costings will apply to motorbility cars.
As others have said the deposit payable varies with the car. I'm all for people having a choice - their choice is not going to affect, worry or inconvenience me.