I’m not picky. I like to go with what I work with; anything the size of a normal car or larger works for me. I like to slowly expand it outwards until it looks how I want it to. I try to avoid heavy-duty vehicles because I like having amphibious vehicles, and heavy-duty vehicles (especially APCs) are generally way, way too heavy to do that.
My current one started as a normal-sized car and turned into this over 69 in-game days. The cargo storage are cargo troughs from Aftershock, and the utilities are all from it too; the cooking rig, MetalMaster forge buddy, fridge, and freezer come from there. I’ve been slimming down my designs as much as possible to see how small I can get, and I’m pretty happy with this result.
My one rule is that I won’t use a Hatchback, Beetle, or any electric car as a base. The first two are far too small, and the second one is far too frail. Not worth it!