Reading your post, Richard, I had to go back to the adhesive instructions and it does indeed say that you have to spray it on both sides. Duhhhh, I just couldn't remember doing it but Madame says that "Yes, we did, you klutz, do you not remember laying it out on the lawn out the back of the house !!!".

So I just stormed off with the cat and I'm now sitting in the car, in the cold until she calls me back in, out of sympathy. I just hope that she doesn't take too long as it's cold out here.

Pierre3.

In my previous life, for several of the cars we were restoring we would do as described: wire brush, normal brush, various thinners, etc.
Then one time one of our upholsterers told me "why you make my life difficult, leaving residues of the goo, or worse, making a mess with the thinner? When the foam starts to disintegrate and is time to remove the old headlining, just lay it on the floor, start the high-pressure washer and just spray it all away!".
It was like my eyes opened for the first time, I have never imagined cleaning a headlining would be so easy!
After that revelation, cleaning and prepping the headlining for reupholster became a very straightforward affair.

I admit I have not tried that on the P38, that was in an the earlier stage ... but all the ones that came later went super easy.

That sounds like a game changer

I suppose that the headliner being a fibreglass panel then it wouldn't be damaged by using a pressure washer to clean it off. Interesting idea, certainly.

But not as big a game changer as sitting on your own, with a cat that doesn't talk, in a cold car, of which you have left the keys inside and you don't want to ring the doorbell to ask Madame if she could give you the keys to start the car and run the heater. That's a game-changer, I can tell you.

Pierre3.

Regarding coating the foam side of the material, we first put the material onto the fiberglass liner, folder half of it back over itself and then started from the middle and worked out from there to avoid the material going on the floor. Disco 2 in my case but much the same (possibly more annoying due to the shelf at the front and the string net things in the middle, and of course a second sunroof to deal with, though no sliding cover on the Disco so that at least is easier!).

Used 3 cans with the Martrim kit, might have been slightly too generous as we barely had any left.

Old material came off very easily (part of the reason I took the headlining out in the first place) the orange stuff came off with a wire brush to a point were we were happy with covering it. Couple of areas ended up slightly creased by getting stuck a little bit too quickly, key thing seeems to be have one person to keep tension on the material and the other to push it into the correct place to stick as needed.

and don't obsess about the grab handle recesses. Get the main flat surfaces flat and wrinkle free first. The handles will hold the material to the headboard perfectly well.