There is a point to which the "sugar cube" and truck seem too bulky and more or less a bit difficult to drive due to their frame and size. And as myself and probably others do, we use vehicles to explore or find nodes in which a required resource is available. Though I understand the secondary nature of the current two vehicles, that being the ability to transport resources between outposts, it feels like a smaller vehicles just for travel would make the process a little refreshing. A dirt bike or ATV would seem to be a reasonable fit, though if you do take my suggestion into consideration I'm sure you will do what ever you feel fits your vision of your game.
