The Ark II and the Roamer were both built by
the Brubaker Group, not Dean Jeffries as has
been reported elsewhere. The reason for this
confusion is that Jeffries designed a similar
vehicle for the movie Damnation Alley and for
years, people assumed the two vehicles were
the same.
The Ark itself was build on a garbage/dump
truck chasis and the main body was fiberglass
modules over a welded steel frame. It was more
of a prop than a vehicle. In show mode (i.e.
fully assembled, as seen on-screen), the actual
driver of the vehicle was not in the cockpit, but
instead sat underneath and in front of the
cockpit, in the "underbelly" of the front section.
In reality, the driver could only see out through
an opening at the top of the front boarding ramp
and a small rectangular hole in the side. To
overcome this problem on location, the fake
driver (in the cockpit where Jonah usually sat)
would have to give the real driver directions for
manuevering. This was okay for location shots
in the California desert areas, but not for
getting to locations requiring actual road use!