Certainly not the same level of need as the fronts, but yhe thought had crossed my mind of doing rear trims as well. It would be pretty simple to do out of ABS plastic other than where it dips in for the arm rest. That would require a multi price construction and gluing together.
Forgoing the arm rest, ABS plastic should be pretty simple and even easier than the fronts
ALSO INTERESTED IN A PAIR OF DOOR CARDS 
I’m in too, if its lighter than the cardboard and made from thin plastic (black ideally).
The said bulge (full length of door card) will be the challenge and not to be underestimated, so professional advice on forming this is recommended as jigs, form tool, heat process method for plastic would be required.
Ah, the door cards: a future project for me, for which I have started to collect the bits.
All ready in my head, I am planning to broadly follow the two documented projects on Turbobricks, creating a later-style door card, including the coveted plastic door pockets, instead of the original of my 1975 car.
Sorry, but I won't partake in the plastic project.
My backing board will be 3mm plywood, as this is more resilient in my experience than masonite, can be stapled and it would hold the tee nuts to hang the door pocket on.
My LHS door card is in a better condition than the right one, and I hope it can be used as a template.
The cover has to be replaced too, as it is in tatters plus I hate the baby-poo colour. I have identified the vinyl from Spotlight to use, with a fake suede insert also from Spotlight.
The bulge/beltline Anthony mentions above will be done by combining a strip of the same ply, plus a strip of thicker self-adhesive foam from Bunnings. As in the Turbobricks projects, I will first staple the upholstery to this beltline and bolt it to the big board, so it will hold the upholstery in the middle, allowing strongly stretching it towards the edges, plus hide the stitching of the vinyl to the suede.
3-4 other under-way projects plus a long overseas trip means I may realistically not start making these this year.
I’d be in for buying a set off you for my 1980 242. What’s the time frame looks like typically?
I’ve got remaking door cards on the todo list for the 242. Just did some for 244 out of Masonite with a costing of fibreglass resin to help with waterproofing.
How did the plastic build go?
I have some plastic Ford door cards for my Thunderbird. The window scraper is usually held on with staples and contact. can't remember if the top metal cap goes back in or not. Best way to make would be to make an inner and outer fiberglass or wood mold and press the heated plastic in between giving you any bends or odd shapes like the original. EDIT: Just checked and the Ford door cards are made of ABS. A 1200x1000mm sheet is about $71
I haven't made any real progress on this yet other than working on it more in my head. Hoping to have something to show in a few months time.
I have been looking into the way the window scraper attaches. I have two different styles of door card, one has metal at the top, one doesn't. I don't know how common that is.
Doesn't anyone else have door cards without the metal bit at the top? It seems uncommon?
The clips that hold in the window scraper on are different between the two styles, complicating the options for reproducing them.
Trying to work out if I should reproduce just one or both styles. Obviously easier to do just one of them.
Picture from the interwebs showing the metal bit I am talking about at the top of the door card.
If it helps, my 1980 model-year but 1979-built GT has the metal, like that picture. ‘Tis how the top of the trim is given it’s shape.
Just looked through eBay and all the door cards for sale had the metal trim.
I think it would have to be a material or maybe a coating that blocks or absorbs noise from outside.
@VolvoHordz - did you end up progressing with this? With some time off over Christmas the door card project is back on the cards for me …
maxthedog haven't had the time to progress it yet. It will definitely happen, but likely now not until early next year.
I’d be keen on a pair
