I know about the panel charge from personal experience. I had a Ford Focus on Motability that was hit on the wing by a woman reversing her Ford Ka in a supermarket carpark. I was stationery at the time.
Very minor damage, a small scratch that was hardly visible, was also sustained on the passenger door. In fact, it was the appointed repair agent that pointed it out to me as I had not seen it myself. When the paperwork came through from Motability following the repairer's report, I was charged what they termed "two panel damage" involving one panel plus adjacent damage. I therefore had to pay the charge for replacing both the wing and the door.
Had I not had the car on Motability, the door damage could have been ignored or repaired far cheaper than the fee per panel charge I had to pay to Motability.
I've had a quick look on the Motability website, but I can't find confirmation of this now. it's probably buried in the detail and to be honest, it doesn't surprise me. It's hardly something Motability would want to advertise.