I want to share a tip that might be useful to many car trimmers.
Some of us find hard to fit a one piece backrest cover with rigid listing wires to give shape. Sometimes we have to resort to 'furniture tricks' such as lacing some strings on 'listing wires' and pull them backwards after unrolling the cover. Or, we have to resort to the use of zippers, velcro or hard back covers to ease the 'fitting procedure'.
A 'plastic coated steel cable' could be bended more than 90 degrees and it recuperates its straight shape immediately. It is more than enough to let us handle the cover while putting the 'hog rings' to the other 'paper coated steel wire' embedded in the foam base.
Just an idea that has worked out for me. https://www.youtube.com/watch?v=uEz1O7cp-_o&t=558s
On the topic of listing wire I wonder if anyone has come across this stuff and maybe (fingers crossed) has a source for it. It's a Typar type listing with a pretty darn ridged plastic end. I pulled this out of the back seat of an Audi (I think) when I robbed the slide out cup holder from the cushion.
We use the above listing,ours has a round section plastic while some of the vw range use a square section so it will fit into clips molded into the foam.I'm in the uk but I'm not sure which supplier we get it from.