I think this is true unless you're hauling something that you really don't want in a closed space with you. Lawn equipment, motorcycle, fertilizer, that sort of thing.
In use: https://commons.wikimedia.org/wiki/File:Bairon-FR-08-chantie...
https://commons.wikimedia.org/wiki/File:Mercedes-Benz_Sprint...
(Can an American tell me what these vehicles are called in the USA?)
Flatbeds.
Here they are very common on construction sites for the messier work (building roads, railways, walls, roofs, forestry etc) but normal vans with a roof are more common for the cleaner work (plumbing, electrics, painting, carpentry etc).