I've really wanted GHQ to do some models that were civilian (trolleys) or could double as civilian vehicles (busses and staff cars).
There are a growing number of GHQ models that are appropriate for conversion to civilian vehicles.
The Opel bus in the OP is of course an excellent choice. Not only is it technically appropriate, it also LOOKS the part.
Presuming we are speaking of the WW2 models (the moderns are even more convertible), here are some that I think make good civilians on my game table.
The Soviet GAZ trucks, in particular the GAZ-AA (double axle), were license-built versions of the Ford Model AA (the truck version of the famed Model A sedan). This was one of the most widely produced and used trucks of the interwar period, and is appropriate as a civilian vehicle in almost any geography.
The ZIS-5 transport bus is appropriate for use as a Soviet civilian carrier.
The Stalinets S-65 tractors that come with various artillery packs are appropriate for civilian use. The S-65 was widely used in agriculture in the Soviet Union during the 1930s.
The open-backed Opel Blitz truck makes an excellent general purpose civilian truck for central Europe from the 1930s through the early 1960s.
The GHQ LRDG truck can be easily enough converted to a Chevy civilian work truck. And just think of all the lovely MGs you'll have as extras when you do!
The Lancia Ro family of trucks (Ro, Ro-ro, and 3Ro) was produced in some numbers for civilians markets in the inter-war period. More than 1,000 of the 3Ro, which GHQ offers in it's Italian forces line-up, were sold to civilian markets prior to the war.
Renault trucks were produced in cab-forward designs starting in about 1934/35 IIRC. But the specific AHS model offered by GHQ was not produced until WW2 (and saw more service with the German army than the French!). But this AHx family remained in production after the war and became reasonably popular as a civilian truck in Europe (I am given to believe).
Of course depending on where you were in Europe, horse wagons were likely to be far more common than trucks and cars in the interwar run-up to WW2.
These wagons in the GHQ German line are easily enough imagined as civilian.
One of my favorites for a wagon is the GHQ Taczanka in the Polish line. Clip off the MG and you have a small civi one or two horse wagon. Or at least, I do.
In years past I kit-bashed a fair number of civilian vehicles from Jeeps, armored cars, and military trucks. I also scratch-built some. I like to sprinkle civis around in my scenarios, and have more than a dozen that I can use at my choice.
Today I think there are enough in production that scratch-building is no longer really necessary, and even kit-bashing can be kept to a minimum. Mostly it's just painting them up differently, and maybe putting some civi-looking payload in a truck or wagon bed.
-Mark
(aka: Mk 1)