With all the (justified) criticism Motability currently receives, one thing they do inarguably well: accommodate your (changing) needs.
We cancelled our running contract early because the seats (in conjunction with the proper firm suspension) were just getting too uncomfortable for my wife – this was done within 5 minutes in a phone call that wasn’t even placed for cancelling the contract in the first place. The guy just said “so you mentioned as an aside, the current car is too uncomfortable for the customer – would you like to leave the contract early and order a replacement immediately?” (the call was originally for asking something in regards to a charger). To which i said “uhm, well technically, sure” – and the next day we ordered a replacement car.
So i wouldn’t get too concerned about whether the car is 100% – if it isn’t, you have options.