Before starting the hobby of Extreme Beekeeping, I often popped down to Salisbury Plain for a bit of mudplugging.
My favourite vehicle was a Simca marmon (SUMB). It was a 1959 Troop carrier, similar to a Unimog that was designed for extremely rough terrain.
It cost me £1,700 from an army surplus and its age and class meant it was Road Tax free, and it did not require an MOT. It also cost me £100 a year to insure.
Being Ex-NATO, and were reserved for the cold war. They are so cheap and commonplace that they are often blown up in war films, particularly when set in Africa or S America.
The bad side is with a Ford 4.2 Flathead engine, and gearbox made for carrying and towing, they do 13Mpg on the straight. However, if you have space to keep it, with no RT and MOT, doing very few miles and are handy with spanner, it could be worth looking into.
I have seen private vehicles with diesels. (the engines were often taken out for other vehicles)
I have owned S1 and S2A landrovers with no legroom (I am over 6ft), but good for a small number of hives.
Range Rovers can carry a similar amount, but in comfort.
I will be buying a new vehicle in Spring for beekeeping. I like the idea of something with a cab and a tow bar so I do not need to drive around wearing a beesuit...