Business Vehicle Lease - Novuna

Donstar

I leased a vehicle for my business through Hitatchi finance that turned into Novuna (not sure if Novuna bought Hitatchi etc)
Anyway on my vehicle being returned a company called Manheim done an inspection and picked up every imperfection under the sun.
Novuna wants to charge me £1800 to cover cost of repair.
a lot of the panels on the Ford Ranger were picked up as 'Poor Paint repair', even the pillar areas between the doors was picked up. Now I know that one panel on the rear was damaged by a trailer and repaired, which was done by a professional paint shop. But I know nowhere else on the vehicle has been touched. Other items picked up were a scratch on a plastic wing protector that I bought and fitted, and the 2 sections being slightly out of alignment ( I fitted them and just held on with Scotch Tape). I contacted Novuna to dispute but they rejected it. I then went to the BVRLA who looked at the photos (and contacted Novuna) and surprise surprise they upheld Novuna's charges. I had grudgingly totalled up other areas of supposed damage (rust under surface on alloy wheels etc) and told them I was willing to pay them £800, but they refused.
My new vehicle has arrived and low and behold it has the same supposed paint defects as the returned one - I've investigated it on Google and its called Orange Peel and is on every vehicle made, though is becoming worse as manufacturers use more environmentally friendly paints, with top end manufacturers (Austin Martin, Ferrari etc) spending a lot of time polishing and buffing vehicles to remove/hide it.
I'm not willing to pay Novuna for what they are classing as poor paint repairs when in fact its the manufacturer and have advised them I'll pay £800, or they can take me to court.
Has anyone else had a problem on returning a vehicle where they claim the paint is poor, but its a manufacturing issue ?
Any ideas on how to resolve the issue, any paint experts willing to back up my views in court etc
Any help greatly appreciated.