Attached are a couple of photos showing what was hidden by the side plastic trim at the rear of the vehicle (front of the rear arches) , recommended to check yours . My welder is fabricating new repair panels as there are non available on the market. One side I had a company who specialise in accident repair and are a UK wide repairer , they quoted me £400 each side and what we have found is the broke all plastic trim retaining clips and just used 'no nails' to refit the trim , and rather tan replace metal just used filer !!! They asked if I wanted a 'quick' job to sell the car or a 'proper' repair - I went for the later and this filler job is what I got ! I will attach

further photos as the job progress.

yup, a truly dreadful piece of design. Had to get my old 02 welded for an MOT, utter horror story under the covers

I would recommend everybody to remove inner wheel plastic covers (you can do this in lift without removing wheel) and check for rust. My left side was little rusty (only surface rust) so i brushed it and painted with hammerite spray in three coats. Right side was without rust but i put also three coats there just to be sure. This is a 2 hour job, so not much time consuming, but you will prolong your vehicle life. Also after painting, you can spray special wax for extra rust protection  RR HSE 4.4 2006 LPG

Yikes !  Too many toys, not enough time

2011 4.4 TDV8 AB Black

Very keen to see how this progresses. Hat off to you for going for repair rather than moving the car on. I need to do this job on my own car, but will have to wait til spring as my garage isn't big enough to get the car in so will be working outdoors.
I'll probably have a go at fabricating the panels over the winter though.
Cheers
Andy

I have put a further update on another similar post with a link to the welder/fabricators Facebook page showing before and after pictures. Absolutely fantastic work , cannot praise or recommend him highly enough !