That's the thing about keeping the old cars running, is that they are getting REALLY old.
My 1965 chevy pickup, a great truck, would be 57 years old today.

I am really thinking about making a truck company loose connection of parts producers that offer all the parts necessary to bolt together your own truck. However, we are probably on the edge of having floaty vehicles. So, what do you do?

And i am unsure of the actual future need.
I don't feel we are going to do as much driving in the future.
And what i should be designing is small farm equipment.
You know, building a little dump truck... something like a Unimog

I just don't know.

Building a larger 3D printer is an issue of accuracy. The bigger the distance, the more the play in the bearings means being way off, and you have to account for metal bending. But, i think you could do this with a camera system that positions the print head via sight, and then just deals with the slop in the robot arm, or the flex in the gantry.