Wigwan,
You would finance anything over just like how you would finance the AP. I don’t think motability actually broker the best deals hence why some lower trims are more expensive than the higher trims on certain models and why, for example, a £30k ford costs £1k AP and a £30k VW costs £4k AP!
I am open to the idea that I might be totally wrong and just barking up the wrong tree – this is just what I came up with as a potential problem solver.