Needed to make some wrecked cars, no idea how to do. Asked on the Lead Adventure Forum and received a few good suggestions: aluminium foil mold layered on an HO scale original, then poured with plaster.
The Blue car is the first attempt, I re-used the “mold” to make the wreck left and down. The orange/brown car is molded with plastiline, more details but a little too neat. Next step: Industrial production of a lot of those wrecks.