promised pictures!
I was browsing around on one of the free STL websites one night, and I came across a nice sandbagged hull-down terrain position.
It wasn't the right scale, but I 'blew it up' to 15mm scale, and then stretched the proportions until it would fit the vehicles I had in mind. The sandbags didn't mind being distorted a little.
The print head on my 3Dprinter was in its final stages, but it managed to print this model. I had to trim off a lot of strings.
I glued the 3Dprint to an inexpensive dollar-store wooden base, then used air-dry clay to contour it into the base.
I painted it up in desert colors, as that was what I needed it for. This would work for WWII, modern or sci-fi. Easy project.