> You can probably manufacture that thing quite easily from basic sheet metal, when you have limited machinery and labour on another planet.

Not if it's made of stainless steel - stuff is hard to cut and hard to weld (though might be easier in a non-oxygen rich environment like Mars).

For ease of manufacture and maintainability, plus a lot of other "pluses" - I actually like this truck:

http://oxgvt.com/

Too bad it's unlikely it will be available for purchase in first world countries, if it ever gets to that phase.